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Solar Energy Science Field Trip

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Take a Field Trip with Science Companion!Join us for a virtual field trip to the largest solar power plant in the US with a very special guest, and then explore our lesson on energy transfers and solar energy from our inquiry-based science curriculum module, Energy.Let us know what you think!

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Page 1: Solar Energy Field Trip

Solar Energy

Science Companion Field TripsA “Science in Real Life” Series

Science Field Trip

A Visit to a Solar Power Plant with a Special Guest

A Lesson on Energy Transfers

from the Energy Module

Student Reference Book Pages

Come on a virtual field trip matching module sample lessons with current events!

www.sciencecompanion.com

Page 2: Solar Energy Field Trip

Solar Energy in Florida!

A special guest was invited for the opening, to celebrate how solar energy can change America...

Can you see all of the solar panels behind the podium?

On October 29, 2009, the world’s largest solar power installation was opened at Florida Power and Light, a utility company in Sarasota, Florida.

90,000 solar panels!

Page 3: Solar Energy Field Trip

Not this guy!(But he came with the special guest...)

We’ll give you a hint!

Rita, Science Companion’s director, was there to greet him, waiting in front of this sign...

“It’s an honor to be here on a very big day not just for Arcadia but for the cause of clean energy in America,” President Obama told the crowd...

“With the flip of a switch, Florida Power and Light has moved the solar panels behind me into a position where they can catch the sun’s rays. And now, for the very first time, a large-scale solar power plant...will deliver electricity produced by the sun to the citizens of the Sunshine State.”

Solar power works through the transfer of energy -- turn the page and find out how!

http://www.sun-sentinel.com/business/sfl-obama-fpl-102809,0,81543.story

Page 4: Solar Energy Field Trip

Levels 4-6

Science Companion®

Energy

Teacher Lesson Manual

Colleen
Text Box
Welcome to a sample of an interactive Science Companion lesson. This file contains Energy Lesson 3, "How Energy Makes Thing Happen." If you're working on a Windows computer using Adobe Acrobat or the Adobe Acrobat Reader, you'll have an easier time with navigation if you give yourself some "Previous View" and "Next View" buttons. These buttons in look like small arrows inside circles. They'll allow you to retrace your jumps within the file, so you don't get lost. - Make sure the Page Navigation toolbar is displayed. (Try View/Toolbars or Tools/Customize Toolbar) - Place the "Previous View" and "Next View" buttons on that toolbar if they are not already there. Let us know how you like this format!
Page 5: Solar Energy Field Trip

DevelopersBelinda Basca, Diane Bell, and Martha Sullivan

EditorsRachel Burke and Wanda Gayle

Technical Art and GraphicsColin Hayes, Anthony Lewis, and Bill Reiswig

Book ProductionHappenstance Type-O-Rama; Picas & Points, Plus (Carolyn Loxton)

Pedagogy and Content AdvisorsJean Bell, Max Bell, Cindy Buchenroth-Martin, Nick Cabot*, Debbie Clement*, Josie Grotenhuis*, Catherine Grubin, Tim Strains*, and Robert Ward

* Indicates a scientist or science educator who contributed advice or expertise, but who is not part of the Chicago Science Group. Ultimately, responsibility for what is included or omitted from our material rests with the Chicago Science Group.

Field Test TeachersJoyce Berry, Suze Bodwell, Jim Elwell, Nancy Florig, David Grelecki, Matt Laughlin, Lisette Mirabile, Valerie Powell, Jen Ryan, Chris Sanborn, Kitty Skow, Jane Stephenson, Will Whitlock, and Nancy Zordan

www.sciencecompanion.com

2009 Edition

Copyright © 2005 Chicago Science Group.

All Rights Reserved

Printed in the United States of America. Except as permitted under the United States Copyright Act, no part of this publication may be reproduced or distributed in any form or by any means or stored in a database or retrieval system without the prior written permission of the publisher.

SCIENCE COMPANION®, EXPLORAGEAR®, the CROSSHATCH Design™ and the WHEEL Design® are trademarks of Chicago Science Group and Chicago Educational Publishing.

ISBN 1-59192-284-4

1 2 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 08

Page 6: Solar Energy Field Trip

Skill Building ActivitiesReading Science Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Measuring Temperature Accurately . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

Making Line Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Designing a Fair Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

Teacher Background Information . . . . . . . . . . . . . . . . . . . 234

Standards and BenchmarksStandards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276

Teacher Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

Table of ContentsSuggested Full Year Schedule . . . . . . . . . .Inside Front Cover

Welcome to Science CompanionPhilosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Finding What You Need in Science Companion . . . . . . . . . . . . . . . . . . 8

Cross-Curricular Integration and Flexible Scheduling . . . . . . . . . . . 10

Differentiating Instruction for Diverse Learners . . . . . . . . . . . . . . . . . 12

Unit OverviewIntroduction to the Energy Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Unit Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Lessons at a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Integrating the Student Reference Book . . . . . . . . . . . . . . . . . . . . . . . . 32

Preparing for the UnitEnergy Science Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Science Library and Web Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Before You Begin Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Lessons1 Energy Is All Around Us* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

2 Energy’s Many Forms* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

3 Energy Transfers: How Energy Makes Things Happen* . . . . . . 80

Teacher Directions: Setting Up the Energy Stations . . . . . . . . . 95

4 Energy Transfers: Making Boats Go . . . . . . . . . . . . . . . . . . . . . . . . 100

Teacher Directions: Making a Solar Pulley . . . . . . . . . . . . . . . . . . 112

5 Hot Water, Cold Water: Transferring Heat Energy* . . . . . . . . . . 116

6 Conductors: Testing the Transfer of Heat Energy* . . . . . . . . . . 132

7 Building a Better Water Bottle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Slowing the Transfer of Heat Energy*

8 Getting More for Less: Energy Efficiency . . . . . . . . . . . . . . . . . . . 164

9 Inventions: Getting Energy to Work for Us* . . . . . . . . . . . . . . . . 180

* Indicates a core lesson

| ENERGY | TablE of CoNTENTs

Page 7: Solar Energy Field Trip

Skill Building ActivitiesReading Science Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Measuring Temperature Accurately . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

Making Line Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Designing a Fair Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

Teacher Background Information . . . . . . . . . . . . . . . . . . . 234

Standards and BenchmarksStandards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

Benchmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276

Teacher Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

Table of ContentsSuggested Full Year Schedule . . . . . . . . . .Inside Front Cover

Welcome to Science CompanionPhilosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Finding What You Need in Science Companion . . . . . . . . . . . . . . . . . . 8

Cross-Curricular Integration and Flexible Scheduling . . . . . . . . . . . 10

Differentiating Instruction for Diverse Learners . . . . . . . . . . . . . . . . . 12

Unit OverviewIntroduction to the Energy Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Unit Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Lessons at a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Integrating the Student Reference Book . . . . . . . . . . . . . . . . . . . . . . . . 32

Preparing for the UnitEnergy Science Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Science Library and Web Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Before You Begin Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Lessons1 Energy Is All Around Us* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

2 Energy’s Many Forms* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

3 Energy Transfers: How Energy Makes Things Happen* . . . . . . 80

Teacher Directions: Setting Up the Energy Stations . . . . . . . . . 95

4 Energy Transfers: Making Boats Go . . . . . . . . . . . . . . . . . . . . . . . . 100

Teacher Directions: Making a Solar Pulley . . . . . . . . . . . . . . . . . . 113

5 Hot Water, Cold Water: Transferring Heat Energy* . . . . . . . . . . 116

6 Conductors: Testing the Transfer of Heat Energy* . . . . . . . . . . 132

7 Building a Better Water Bottle: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Slowing the Transfer of Heat Energy*

8 Getting More for Less: Energy Efficiency . . . . . . . . . . . . . . . . . . . 164

9 Inventions: Getting Energy to Work for Us* . . . . . . . . . . . . . . . . 180

* Indicates a core lesson

ENERGY | TablE of CoNTENTs |

Page 8: Solar Energy Field Trip

6

PhilosophyAlmost anyone who has spent time with children is struck by the tremendous energy they expend exploring their world. They ask “why” and “how.” They want to see and touch. They use their minds and senses to explore the things they encounter and wonder about. In other words, children are already equipped with the basic qualities that make a good scientist.

The goal of the Science Companion curriculum is to respond to and nourish students’ scientific dispositions by actively engaging their interests and enhancing their powers of inquiry, observation, and reflection. Learning by doing is central to this program.

Each Science Companion lesson incorporates interesting and relevant scientific content, as well as science values, attitudes, and skills that children in the elementary grades should begin to develop. These “habits of mind,” along with science content knowledge, are crucial for building science literacy and they are an integral part of the Science Companion program. Be aware of them and reinforce them as you work with students. With experience, students will develop the ways they demonstrate and use the following scientific habits of mind.

Habits of MindWondering and thinking about the natural and physical worldStudents’ curiosity is valued, respected, and nurtured. Their questions and theories about the world around them are important in setting direction and pace for the curriculum. Children are encouraged to revise and refine their questions and ideas as they gain additional information through a variety of sources and experiences.

Seeking answers through exploration and investigationStudents actively seek information and answers to their questions by trying things out and making observations. They continually revise their understanding based on their experiences. Through these investigations, children learn firsthand about the “scientific method.” They also see that taking risks and making mistakes are an important part of science and of learning in general.

Pursuing ideas in depthStudents have the opportunity to pursue ideas and topics fully, revisiting them and making connections to other subjects and other areas in their lives.

Observing carefullyStudents are encouraged to attend to details. They are taught to observe with multiple senses and from a variety of perspectives. They use tools, such as magnifying lenses, balance scales, rulers, and clocks, to enhance their observations. Students use their developing mathematics and literacy skills to describe, communicate, and record their observations in age-appropriate ways.

Communicating clearlyStudents are asked to describe their observations and articulate their thinking and ideas using a variety of communication tools, including speaking, writing, and drawing. They learn that record keeping is a valuable form of communication for oneself and others. Children experience how working carefully improves one’s ability to use one’s work as a tool for communication.

Collaborating and sharingStudents come to know that their ideas, questions, observations, and work have value. At the same time, they learn that listening is vitally important, and that exchanging ideas with one another builds knowledge and enhances understanding. Children discover that they can gain more knowledge as a group than as individuals, and that detailed observations and good ideas emerge from collaboration.

Developing critical response skillsStudents ask, “How do you know?” when appropriate, and are encouraged to attempt to answer when this question is asked of them. This habit helps develop the critical response skills needed by every scientist.

WE

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| ENERGY | PhilosoPhY

Page 9: Solar Energy Field Trip

PhilosophyAlmost anyone who has spent time with children is struck by the tremendous energy they expend exploring their world. They ask “why” and “how.” They want to see and touch. They use their minds and senses to explore the things they encounter and wonder about. In other words, children are already equipped with the basic qualities that make a good scientist.

The goal of the Science Companion curriculum is to respond to and nourish students’ scientific dispositions by actively engaging their interests and enhancing their powers of inquiry, observation, and reflection. Learning by doing is central to this program.

Each Science Companion lesson incorporates interesting and relevant scientific content, as well as science values, attitudes, and skills that children in the elementary grades should begin to develop. These “habits of mind,” along with science content knowledge, are crucial for building science literacy and they are an integral part of the Science Companion program. Be aware of them and reinforce them as you work with students. With experience, students will develop the ways they demonstrate and use the following scientific habits of mind.

Habits of MindWondering and thinking about the natural and physical worldStudents’ curiosity is valued, respected, and nurtured. Their questions and theories about the world around them are important in setting direction and pace for the curriculum. Children are encouraged to revise and refine their questions and ideas as they gain additional information through a variety of sources and experiences.

Seeking answers through exploration and investigationStudents actively seek information and answers to their questions by trying things out and making observations. They continually revise their understanding based on their experiences. Through these investigations, children learn firsthand about the “scientific method.” They also see that taking risks and making mistakes are an important part of science and of learning in general.

Pursuing ideas in depthStudents have the opportunity to pursue ideas and topics fully, revisiting them and making connections to other subjects and other areas in their lives.

Observing carefullyStudents are encouraged to attend to details. They are taught to observe with multiple senses and from a variety of perspectives. They use tools, such as magnifying lenses, balance scales, rulers, and clocks, to enhance their observations. Students use their developing mathematics and literacy skills to describe, communicate, and record their observations in age-appropriate ways.

Communicating clearlyStudents are asked to describe their observations and articulate their thinking and ideas using a variety of communication tools, including speaking, writing, and drawing. They learn that record keeping is a valuable form of communication for oneself and others. Children experience how working carefully improves one’s ability to use one’s work as a tool for communication.

Collaborating and sharingStudents come to know that their ideas, questions, observations, and work have value. At the same time, they learn that listening is vitally important, and that exchanging ideas with one another builds knowledge and enhances understanding. Children discover that they can gain more knowledge as a group than as individuals, and that detailed observations and good ideas emerge from collaboration.

Developing critical response skillsStudents ask, “How do you know?” when appropriate, and are encouraged to attempt to answer when this question is asked of them. This habit helps develop the critical response skills needed by every scientist.

WE

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TO

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ENERGY | PhilosoPhY |

Page 10: Solar Energy Field Trip

�0

Lesson Energy Transfers: How Energy Makes Things Happen

A QUICK LOOK

Big Idea

Energy can move, or transfer, from place to place. Sometimes it changes form as it transfers.

OverviewStudents operate a variety of toys to figure out the type of energy transfers that occur in each one. They work in small groups, rotating through a series of “energy stations.”

Process Skills Key notes• Reasoning

• Explaining

• Communicating

• Schedule three sessions for this lesson.

• For the exploration, set up nine stations with enough space for small groups of students to gather around and operate each toy. See the Teacher Directions “Setting up the Energy Stations” on pages 95–98 for details.

• A solar-powered propeller and solar-activated colored beads are used in this lesson. If sunlight is not readily available in your classroom, use the compact florescent light bulb and clamp lamp provided in the ExploraGear to activate these items instead.

• For more information about the science content in this lesson, see the “Transfer of Energy” section of the Teacher Background Information on page 242.

E n E R G Y

C L U S T E R 2EnErgy transfErs

32

| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN

Page 11: Solar Energy Field Trip

NoTes

�1ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN |

Standards and BenchmarksAs they move through the energy stations, students deepen their understanding of Atlas of Scientific Literacy Benchmark 4E/E4: “Many events involve transfer of energy from one object to another,” and Atlas of Scientific Literacy Benchmark 4E/M2: “Most processes involve the transfer of energy from one system to another. Energy can be transferred in different ways.”

When the children identify the various energy forms being transferred as the toys are operated, they also expand their awareness of Physical Science Standard B (Transfer of Energy): “Energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical,” and Atlas of Scientific Literacy Benchmark 4E/M4: “Energy appears in different forms. Motion energy is associated with the speed of an object. Heat energy is associated with the temperature of an object. Gravitational energy is associated with the height of an object above a reference point. Elastic energy is associated with the stretching of an elastic object. Chemical energy is associated with the chemical composition of a substance.”

Lesson GoalRecognize that energy moves from place to place and changes forms to make things happen.

Assessment Options• Prior to the lesson, have students use their science notebook

journal section to respond to this question: Can energy move from one object to another? If so, give some examples.

• After the lesson, have students revisit the writing assignment to demonstrate how their understanding of energy transfers has grown. Consider using criterion B on Assessment 1 to note students’ progress.

• Review the Family Link Homework “Toy Box Science” to see whether students were able to independently trace the flow of energy in one of their own toys. Use criterion B on Assessment 1 to document their understanding at this time.

Energy Transfers: How Energy Makes Things Happen

A QUICK LOOK

Big Idea

Energy can move, or transfer, from place to place. Sometimes it changes form as it transfers.

OverviewStudents operate a variety of toys to figure out the type of energy transfers that occur in each one. They work in small groups, rotating through a series of “energy stations.”

Process Skills Key notes• Reasoning

• Explaining

• Communicating

• Schedule three sessions for this lesson.

• For the exploration, set up nine stations with enough space for small groups of students to gather around and operate each toy. See the Teacher Directions “Setting up the Energy Stations” on pages 95–98 for details.

• A solar-powered propeller and solar-activated colored beads are used in this lesson. If sunlight is not readily available in your classroom, use the compact florescent light bulb and clamp lamp provided in the ExploraGear to activate these items instead.

• For more information about the science content in this lesson, see the “Transfer of Energy” section of the Teacher Background Information on page 242.

Teacher Master 3, Assessment 1

Lesson 32

Page 12: Solar Energy Field Trip

�2

PreparationSchedule three sessions for this lesson. Conduct the introductory demonstration in Session 1, rotate groups through the nine energy stations in Session 2, and follow up with the reflective discussion in Session 3.

Session 1q Locate the ExploraGear solar kit and make the solar-powered

propeller:

a. Attach the propeller to the shaft projecting from the motor.

b. Connect the wires of the solar panel to the wires of the motor.

q Prop the motor and propeller up on a small box or block as shown so that the propeller can spin freely without obstruction.

q Since light energy activates the solar propeller, position the solar panel towards a source of light energy. If enough sunlight is not available in your classroom, use the compact florescent light bulb and clamp lamp provided in the ExploraGear instead. Allow several minutes for the light bulb to warm up before doing the demonstration.

Materials

Item Quantity notesExploraGear

Clamp lamp (optional) 1 Use with a compact fluorescent light bulb to activate the solar propeller if sunlight is not available. Also used for magic bracelet beads.

Compact fluorescent light bulb (CFL), 26W 1 Use with clamp lamp to energize the solar propeller.

Solar kit To make solar propeller.

Classroom Supplies

Box or block, small 1 To prop up solar propeller.

Energy stations 9 For Session 2 exploration.

Hair dryer (optional) 1 To demonstrate that the solar panel is not activated by heat.

Overhead marker 1 To map energy transfers on an overhead transparency.

Overhead projector 1 To show overhead transparency.

Curriculum Items

Overhead Transparency “Mapping Energy Transfers”

Energy Science Notebook, pages 4–13

Energy Student Reference Book, pages 13–24 and 129-146

Teacher Directions “Setting up the Energy Stations”

Teacher Master “Energy Station Directions”

Energy Assessment 1 “Energy Forms and Transfers” (optional)

Family Link Homework “Toy Box Science”

NoTes

| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN

Page 13: Solar Energy Field Trip

NoTes

�3

PreparationSchedule three sessions for this lesson. Conduct the introductory demonstration in Session 1, rotate groups through the nine energy stations in Session 2, and follow up with the reflective discussion in Session 3.

Session 1q Locate the ExploraGear solar kit and make the solar-powered

propeller:

a. Attach the propeller to the shaft projecting from the motor.

b. Connect the wires of the solar panel to the wires of the motor.

q Prop the motor and propeller up on a small box or block as shown so that the propeller can spin freely without obstruction.

q Since light energy activates the solar propeller, position the solar panel towards a source of light energy. If enough sunlight is not available in your classroom, use the compact florescent light bulb and clamp lamp provided in the ExploraGear instead. Allow several minutes for the light bulb to warm up before doing the demonstration.

Materials

Item Quantity notesExploraGear

Clamp lamp (optional) 1 Use with a compact fluorescent light bulb to activate the solar propeller if sunlight is not available. Also used for magic bracelet beads.

Compact fluorescent light bulb (CFL), 26W 1 Use with clamp lamp to energize the solar propeller.

Solar kit To make solar propeller.

Classroom Supplies

Box or block, small 1 To prop up solar propeller.

Energy stations 9 For Session 2 exploration.

Hair dryer (optional) 1 To demonstrate that the solar panel is not activated by heat.

Overhead marker 1 To map energy transfers on an overhead transparency.

Overhead projector 1 To show overhead transparency.

Curriculum Items

Overhead Transparency “Mapping Energy Transfers”

Energy Science Notebook, pages 4–13

Energy Student Reference Book, pages 13–24 and 129-146

Teacher Directions “Setting up the Energy Stations”

Teacher Master “Energy Station Directions”

Energy Assessment 1 “Energy Forms and Transfers” (optional)

Family Link Homework “Toy Box Science”

ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN |

Page 14: Solar Energy Field Trip

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| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN�4

Teaching the LessonSESSIOn 1

Engage

Sensory Observation

Have the students reflect on the “I Wonder” circle as they observe the solar propeller responding to sunlight. Help them see how observations (the propeller spins when sunlight hits the panel, but stops when sunlight is absent) lead to discovery (light energy is being transferred from the sun to activate the solar panel).

1. Show the class the solar propeller. Without explaining how it works, allow students to see how sunlight striking the solar panel makes the propeller spin. Cover up the solar panel with your hand to make it stop.

Teacher NoTe: If it is a sunny day with patchy clouds, simply set the unit in a window and allow students to figure out on their own that the propeller spins rapidly when the sun shines and slows down or even stops when passing clouds block the sun.

2. Discuss where the propeller gets the energy to spin. (Students should recognize that when light shines on the panel the propeller has the energy to spin and when the light is blocked the propeller no longer has the energy to spin.)

Teacher NoTe: If some students believe that the sun’s or the lamp’s heat rather than its light powers the propeller, you can direct hot air from a hair dryer onto the solar panel to show that heat energy alone does not cause the propeller to spin.

3. Introduce the term energy transfer to describe instances where energy moves from one place or object to another (such as from the sun to the solar panel), or changes from one form to another (such as in the solar panel itself, where light energy is changed to electrical energy). Tell the class that they have three fun science sessions to look forward to—they get to explore energy transfers using toys.

Session 2q Set up the nine energy stations as described in the Teacher

Directions “Setting up the Energy Stations” on pages 95–98. Follow these steps before setting up the stations:

a. Make a copy of the Teacher Master “Energy Station Directions.” Cut along the dotted lines to create separate toy operation directions for each station.

b. Bright, direct sunlight is needed to activate the magic bracelet at Energy Station 9. They will not activate using an incandescent bulb or out of direct sunlight. If sunlight is not available, use the compact fluorescent light bulb and clamp lamp provided in the ExploraGear. Allow time for the light bulb to warm up before sending students to the station.

c. Allow ample time to run through each station after set-up to troubleshoot any problems and ensure that the toys are working properly.

q Copy the Family Link Homework “Toy Box Science” to send home with the students.

Using the Student Reference Book• After Session 1, use Chapter 2 of the student reference book to

reinforce the concept of energy transfers.

• (Optional) At the end of this lesson, refer students to the timeline “A Walk Through Energy History” on page 129–146 of the student reference book. Challenge the class to identify the energy transfers associated with several of the timeline events.

Vocabularyenergy transfer . . . . . When energy moves from one object or

place to another or changes from one form to another.

solar energy . . . . . . . . Energy transferred from the sun. Solar energy travels to Earth through space and provides warmth, light, and energy for plant growth.

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Teaching the LessonSESSIOn 1

Engage

Sensory Observation

Have the students reflect on the “I Wonder” circle as they observe the solar propeller responding to sunlight. Help them see how observations (the propeller spins when sunlight hits the panel, but stops when sunlight is absent) lead to discovery (light energy is being transferred from the sun to activate the solar panel).

1. Show the class the solar propeller. Without explaining how it works, allow students to see how sunlight striking the solar panel makes the propeller spin. Cover up the solar panel with your hand to make it stop.

Teacher NoTe: If it is a sunny day with patchy clouds, simply set the unit in a window and allow students to figure out on their own that the propeller spins rapidly when the sun shines and slows down or even stops when passing clouds block the sun.

2. Discuss where the propeller gets the energy to spin. (Students should recognize that when light shines on the panel the propeller has the energy to spin and when the light is blocked the propeller no longer has the energy to spin.)

Teacher NoTe: If some students believe that the sun’s or the lamp’s heat rather than its light powers the propeller, you can direct hot air from a hair dryer onto the solar panel to show that heat energy alone does not cause the propeller to spin.

3. Introduce the term energy transfer to describe instances where energy moves from one place or object to another (such as from the sun to the solar panel), or changes from one form to another (such as in the solar panel itself, where light energy is changed to electrical energy). Tell the class that they have three fun science sessions to look forward to—they get to explore energy transfers using toys.

Session 2q Set up the nine energy stations as described in the Teacher

Directions “Setting up the Energy Stations” on pages 95–98. Follow these steps before setting up the stations:

a. Make a copy of the Teacher Master “Energy Station Directions.” Cut along the dotted lines to create separate toy operation directions for each station.

b. Bright, direct sunlight is needed to activate the magic bracelet at Energy Station 9. They will not activate using an incandescent bulb or out of direct sunlight. If sunlight is not available, use the compact fluorescent light bulb and clamp lamp provided in the ExploraGear. Allow time for the light bulb to warm up before sending students to the station.

c. Allow ample time to run through each station after set-up to troubleshoot any problems and ensure that the toys are working properly.

q Copy the Family Link Homework “Toy Box Science” to send home with the students.

Using the Student Reference Book• After Session 1, use Chapter 2 of the student reference book to

reinforce the concept of energy transfers.

• (Optional) At the end of this lesson, refer students to the timeline “A Walk Through Energy History” on page 129–146 of the student reference book. Challenge the class to identify the energy transfers associated with several of the timeline events.

Vocabularyenergy transfer . . . . . When energy moves from one object or

place to another or changes from one form to another.

solar energy . . . . . . . . Energy transferred from the sun. Solar energy travels to Earth through space and provides warmth, light, and energy for plant growth.

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Introductory Discussion—Modeling How to Map Energy Transfers1. Show students the main components of the solar propeller:

a solar panel, a set of wires, a propeller, and a motor that produces a spinning motion.

2. Solicit students’ ideas while you describe how energy transfers through the components, changing from one form to another to make the propeller spin. Questions to encourage critical thinking include:

• What forms of energy are evident as the solar propeller operates?

• Does energy change from one form to another? If so, in what order?

(Light energy from the sun transfers to the solar cells in the solar panel; in the cells, the light energy is transferred to electrical energy; the electrical energy travels through the wires to the motor, where it is transferred into motion energy.)

3. Using the Overhead Transparency “Mapping Energy Transfers” and an erasable overhead marker, show students how to map the energy transfers that made the solar propeller spin. As you connect the different energy forms on the overhead transparency, have students mirror your mapping on page 4 of their science notebooks. Use the following steps and sample energy map to help with this task.

a. Label shapes with the type of energy involved.

b. Draw arrows to map how energy transfers from one form to another as the solar propeller operates.

c. Write a brief description next to your arrows to add details about the forms of energy involved and how they transfer.

4. Wipe off the overhead transparency and ask for volunteers to map some additional examples of energy transfers. Let students use their own ideas of examples of energy transfers or choose from a list you provide.

• Provide at least one example that could be interpreted a variety of ways, such as a hammer raised to drive in a nail. Encourage alternative interpretations. (Some students might see gravitational energy as the energy source that transfers to motion energy which drives the nail in. Others may cite muscle power—chemical energy—transferring to motion energy to drive the nail in. A few students may suggest that sound energy should be included on the map because of the sound the hammer makes as it hits the nail.)

• Use this activity as an opportunity to reinforce the idea that there isn’t one “correct” answer. The objective is for students to notice how energy changes as things happen.

5. Assign Chapter 2 of the student reference book to reinforce the concept of energy transfers.

Overhead Transparency: “Mapping Energy Transfers”

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Introductory Discussion—Modeling How to Map Energy Transfers1. Show students the main components of the solar propeller:

a solar panel, a set of wires, a propeller, and a motor that produces a spinning motion.

2. Solicit students’ ideas while you describe how energy transfers through the components, changing from one form to another to make the propeller spin. Questions to encourage critical thinking include:

• What forms of energy are evident as the solar propeller operates?

• Does energy change from one form to another? If so, in what order?

(Light energy from the sun transfers to the solar cells in the solar panel; in the cells, the light energy is transferred to electrical energy; the electrical energy travels through the wires to the motor, where it is transferred into motion energy.)

3. Using the Overhead Transparency “Mapping Energy Transfers” and an erasable overhead marker, show students how to map the energy transfers that made the solar propeller spin. As you connect the different energy forms on the overhead transparency, have students mirror your mapping on page 4 of their science notebooks. Use the following steps and sample energy map to help with this task.

a. Label shapes with the type of energy involved.

b. Draw arrows to map how energy transfers from one form to another as the solar propeller operates.

c. Write a brief description next to your arrows to add details about the forms of energy involved and how they transfer.

4. Wipe off the overhead transparency and ask for volunteers to map some additional examples of energy transfers. Let students use their own ideas of examples of energy transfers or choose from a list you provide.

• Provide at least one example that could be interpreted a variety of ways, such as a hammer raised to drive in a nail. Encourage alternative interpretations. (Some students might see gravitational energy as the energy source that transfers to motion energy which drives the nail in. Others may cite muscle power—chemical energy—transferring to motion energy to drive the nail in. A few students may suggest that sound energy should be included on the map because of the sound the hammer makes as it hits the nail.)

• Use this activity as an opportunity to reinforce the idea that there isn’t one “correct” answer. The objective is for students to notice how energy changes as things happen.

5. Assign Chapter 2 of the student reference book to reinforce the concept of energy transfers.

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SESSIOn 3

Big Idea

Energy can move, or transfer, from place to place. Sometimes it changes form as it transfers.

Reflect and Discuss

Teacher NoTe: Students’ understanding of energy transfers, as evidenced by their energy maps, may vary greatly. Some students may simply map the first and last forms of energy noted rather than any intermediary forms. Others may extend their thinking far beyond the basics, including things like the transfer of the chemical energy in the food they eat to the motion energy of their muscles, which in turn was transferred to the toy during operation. Accept all reasonable explanations and focus on each student’s rationale rather than highlighting a single “correct” energy map for each toy.

SharingInitiate reflections on the energy mapping activity and encourage groups to share their findings.

• What was their favorite toy?

• Which toy was most difficult to figure out? Why was it hard to figure out what kinds of energy transfers made this toy run?

• When was it most clear that energy was being transferred? What made it so obvious?

• Was it always possible to know for sure what kinds of transfers occurred? Why or why not? (No! Students were not directed to open the energy ball, for example, to see what was happening inside.)

• Could they still tell that energy was transferred even when the parts were hidden from view or too hard to understand? How? (Students should recognize that the new forms of energy they observed while operating the toys must mean that energy was transferred—even if the mechanism was unclear.)

• Did they observe energy changing forms at any of the stations? (Yes) Did it always change form? (No) Does energy sometimes change into more than one form? (Yes)

• Were there any stations where the members of their group could not agree on the energy transfers that occurred? (Walk the class through any disputed energy transfers. Allow students to explain their reasoning; dispel misconceptions and help them grasp alternative explanations when appropriate.)

SESSIOn 2

Explore

Mapping Energy Transfers in Toys

Teacher NoTe: Familiarize yourself with the explanations on pages 97–98 of how the more complex toys work.

1. Explain the energy mapping activity and answer any questions. Outline these steps:

a. Take turns with other groups visiting nine energy stations, each set up with a different toy and instructions for operating the toy.

b. At each station, operate the toy, figure out what kinds of energy transfers make the toy work, and create a map of those transfers with the group. (Emphasize the importance of observing the toys in action, taking the time needed to think carefully about what the toys do, and considering the opinions of other group members before mapping the energy transfers.)

c. Complete the energy maps on science notebook pages 5–13. Point out that the students need to fill in the name of the toy being operated at the top of each science notebook page.

d. Use the glossary in the science notebook as needed to review descriptions of any of the energy forms.

MaNageMeNT NoTe: Before dividing the class into groups, decide on a rotation strategy. You can have groups rotate in unison after a set amount of time or allow groups to operate at their own pace, moving on to open stations as they become available.

2. Divide the class into nine groups and direct them to the appropriate stations.

Teacher NoTe: Rotate through the stations as groups visit them. Listen for particularly interesting debates regarding the energy transfers that occur. You may wish to revisit these debates during the reflective discussion.

3. Send home the Family Link “Toy Box Science” to provide students with an opportunity to independently trace the flow of energy through a toy of their choice.

Science Notebook pages 5–13

Teacher Master 41, Family Link

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SESSIOn 3

Big Idea

Energy can move, or transfer, from place to place. Sometimes it changes form as it transfers.

Reflect and Discuss

Teacher NoTe: Students’ understanding of energy transfers, as evidenced by their energy maps, may vary greatly. Some students may simply map the first and last forms of energy noted rather than any intermediary forms. Others may extend their thinking far beyond the basics, including things like the transfer of the chemical energy in the food they eat to the motion energy of their muscles, which in turn was transferred to the toy during operation. Accept all reasonable explanations and focus on each student’s rationale rather than highlighting a single “correct” energy map for each toy.

SharingInitiate reflections on the energy mapping activity and encourage groups to share their findings.

• What was their favorite toy?

• Which toy was most difficult to figure out? Why was it hard to figure out what kinds of energy transfers made this toy run?

• When was it most clear that energy was being transferred? What made it so obvious?

• Was it always possible to know for sure what kinds of transfers occurred? Why or why not? (No! Students were not directed to open the energy ball, for example, to see what was happening inside.)

• Could they still tell that energy was transferred even when the parts were hidden from view or too hard to understand? How? (Students should recognize that the new forms of energy they observed while operating the toys must mean that energy was transferred—even if the mechanism was unclear.)

• Did they observe energy changing forms at any of the stations? (Yes) Did it always change form? (No) Does energy sometimes change into more than one form? (Yes)

• Were there any stations where the members of their group could not agree on the energy transfers that occurred? (Walk the class through any disputed energy transfers. Allow students to explain their reasoning; dispel misconceptions and help them grasp alternative explanations when appropriate.)

SESSIOn 2

Explore

Mapping Energy Transfers in Toys

Teacher NoTe: Familiarize yourself with the explanations on pages 97–98 of how the more complex toys work.

1. Explain the energy mapping activity and answer any questions. Outline these steps:

a. Take turns with other groups visiting nine energy stations, each set up with a different toy and instructions for operating the toy.

b. At each station, operate the toy, figure out what kinds of energy transfers make the toy work, and create a map of those transfers with the group. (Emphasize the importance of observing the toys in action, taking the time needed to think carefully about what the toys do, and considering the opinions of other group members before mapping the energy transfers.)

c. Complete the energy maps on science notebook pages 5–13. Point out that the students need to fill in the name of the toy being operated at the top of each science notebook page.

d. Use the glossary in the science notebook as needed to review descriptions of any of the energy forms.

MaNageMeNT NoTe: Before dividing the class into groups, decide on a rotation strategy. You can have groups rotate in unison after a set amount of time or allow groups to operate at their own pace, moving on to open stations as they become available.

2. Divide the class into nine groups and direct them to the appropriate stations.

Teacher NoTe: Rotate through the stations as groups visit them. Listen for particularly interesting debates regarding the energy transfers that occur. You may wish to revisit these debates during the reflective discussion.

3. Send home the Family Link “Toy Box Science” to provide students with an opportunity to independently trace the flow of energy through a toy of their choice.

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Ongoing Learning

Science CenterMaterials: Additional toys that run as a result of energy transfers, living organism setups that demonstrate the transfer of energy, and copies of the overhead transparency “Mapping Energy Transfers”

• Place additional toys that run as a result of energy transfers in the Science Center. Possibilities include a pinwheel, a rubber band-powered airplane, a pull-back car, eye poppers (flexible, vinyl half balls that pop up when you flip them inside-out), a Jack-in-the-box, a hand-powered flashlight (with a tiny electrical generator inside instead of batteries) that is activated when the flashlight handle is squeezed, a toddler’s wooden pounding-bench, wind-up toys, and a lava lamp. Provide extra copies of energy maps for students to fill in as they operate the toys. (Use the Overhead Transparency “Mapping Energy Transfers” with a blank piece of paper placed behind it to make extra copies.) Encourage the class to bring in “energized” toys from home to add to the collection.

• Provide several setups that demonstrate how energy transfers in living things, such as a plant in the sunlight, mushrooms on a log, and a leaf-eating insect in a jar full of leaves. Have extra copies of energy maps available for students to map the energy transfers that occur in each of the setups. (Plant = light to chemical; mushroom = chemical to chemical; leaf-eating insect = chemical [leaf matter] to chemical [insect matter] and motion [insect’s movements])

Family LinkIn the Family Link Homework “Toy Box Science” students are asked to describe the energy transfers that occur when they operate one of their own toys. This Family Link can be used as a formative assessment.

A bonus activity is also described, which encourages interested students to chew a wintergreen-flavored Lifesaver® in a dark room. They observe the light emitted as the candy breaks apart and consider the energy transfer involved, which is motion energy (of the teeth) to light energy.

Teacher NoTe: The actual process is really much more complex and involves molecules and the electric charges within them. As you chew, the chemical bonds of the sugar molecules in the lifesavers are torn apart, producing electrical energy among the pieces. This energy is transferred to other molecules which then give it off as light. This happens with most sugars, but the molecule that supplies the wintergreen flavor causes the process to produce more visible light than usual. Producing light energy by rubbing or crushing certain molecules is known as triboluminescence.

MaintenanceCollect and review the Family Link Homework “Toy Box Science” to see whether students were able to trace the flow of energy in one of their own toys independently.

Synthesizing1. Have the class reflect on the exploration and answer the

following questions to reach the conclusion that every time something happens, energy is being transferred:

• Do they think that energy can make something happen (such as making toys work) without being transferred?

• What do their observations indicate?

2. Help students think of energy transfers outside their classroom experiences. Where else do energy transfers occur? Remind them of the energy transfers they read about in their student reference books, if necessary.

3. (Optional) Build on students’ curiosity and questions about the appearance of energy loss to create a foundation for understanding the conservation of energy in more advanced science classes:

• Did the energy seem to run out of any toys at some stations? (The spinning top, bouncing ball, and dominoes may seem to “run out of energy.)

standards and benchmarks connectionHaving students begin thinking about how “energy can change from one form to another, although in the process some energy is always converted to heat” provides an opportunity to introduce students to The Designed World Standard C (Energy Sources and Use) for grades 6–8. Children will build on this introduction in later grades.

• If a toy’s energy seemed to run out, why do they think this happened? Where did the energy go? (Some students may be able to describe what friction does—“the air slowed down the spinning top.” Reinforce this awareness, pointing out other instances where friction occurs—when they rub their hands back and forth, for example. Help them see that, instead of “running out,” the energy is transferred to heat energy.)

Teacher NoTe: Consider teaching the Further Science Exploration “Friction Produces Heat Energy” to help dispel the notion that energy disappears.

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Ongoing Learning

Science CenterMaterials: Additional toys that run as a result of energy transfers, living organism setups that demonstrate the transfer of energy, and copies of the overhead transparency “Mapping Energy Transfers”

• Place additional toys that run as a result of energy transfers in the Science Center. Possibilities include a pinwheel, a rubber band-powered airplane, a pull-back car, eye poppers (flexible, vinyl half balls that pop up when you flip them inside-out), a Jack-in-the-box, a hand-powered flashlight (with a tiny electrical generator inside instead of batteries) that is activated when the flashlight handle is squeezed, a toddler’s wooden pounding-bench, wind-up toys, and a lava lamp. Provide extra copies of energy maps for students to fill in as they operate the toys. (Use the Overhead Transparency “Mapping Energy Transfers” with a blank piece of paper placed behind it to make extra copies.) Encourage the class to bring in “energized” toys from home to add to the collection.

• Provide several setups that demonstrate how energy transfers in living things, such as a plant in the sunlight, mushrooms on a log, and a leaf-eating insect in a jar full of leaves. Have extra copies of energy maps available for students to map the energy transfers that occur in each of the setups. (Plant = light to chemical; mushroom = chemical to chemical; leaf-eating insect = chemical [leaf matter] to chemical [insect matter] and motion [insect’s movements])

Family LinkIn the Family Link Homework “Toy Box Science” students are asked to describe the energy transfers that occur when they operate one of their own toys. This Family Link can be used as a formative assessment.

A bonus activity is also described, which encourages interested students to chew a wintergreen-flavored Lifesaver® in a dark room. They observe the light emitted as the candy breaks apart and consider the energy transfer involved, which is motion energy (of the teeth) to light energy.

Teacher NoTe: The actual process is really much more complex and involves molecules and the electric charges within them. As you chew, the chemical bonds of the sugar molecules in the lifesavers are torn apart, producing electrical energy among the pieces. This energy is transferred to other molecules which then give it off as light. This happens with most sugars, but the molecule that supplies the wintergreen flavor causes the process to produce more visible light than usual. Producing light energy by rubbing or crushing certain molecules is known as triboluminescence.

MaintenanceCollect and review the Family Link Homework “Toy Box Science” to see whether students were able to trace the flow of energy in one of their own toys independently.

Synthesizing1. Have the class reflect on the exploration and answer the

following questions to reach the conclusion that every time something happens, energy is being transferred:

• Do they think that energy can make something happen (such as making toys work) without being transferred?

• What do their observations indicate?

2. Help students think of energy transfers outside their classroom experiences. Where else do energy transfers occur? Remind them of the energy transfers they read about in their student reference books, if necessary.

3. (Optional) Build on students’ curiosity and questions about the appearance of energy loss to create a foundation for understanding the conservation of energy in more advanced science classes:

• Did the energy seem to run out of any toys at some stations? (The spinning top, bouncing ball, and dominoes may seem to “run out of energy.)

standards and benchmarks connectionHaving students begin thinking about how “energy can change from one form to another, although in the process some energy is always converted to heat” provides an opportunity to introduce students to The Designed World Standard C (Energy Sources and Use) for grades 6–8. Children will build on this introduction in later grades.

• If a toy’s energy seemed to run out, why do they think this happened? Where did the energy go? (Some students may be able to describe what friction does—“the air slowed down the spinning top.” Reinforce this awareness, pointing out other instances where friction occurs—when they rub their hands back and forth, for example. Help them see that, instead of “running out,” the energy is transferred to heat energy.)

Teacher NoTe: Consider teaching the Further Science Exploration “Friction Produces Heat Energy” to help dispel the notion that energy disappears.

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Energy Transfers and the Food Chain

nature’s recyclers connectionExploring food chains with a focus on energy is an ideal way to build upon a key concept from the Science Companion Level 4 Nature’s Recyclers Unit—the recycling of matter through ecosystems. While the total amount of matter at each level of a food chain remains constant, the energy available at each level diminishes as some chemical energy is transformed into forms such as heat and motion that are no longer available to the next level.

Provide opportunities for students to trace the transfer of chemical energy through the food chain. Focus on the decrease in available chemical energy at each stage in a food chain. Discuss some of the energy transfers that account for this decrease. (Living organisms generate heat—a chemical-to-heat energy transfer. This heat energy is in turn transferred to the organisms’ surroundings, making it unavailable to the next level of the food chain. Some chemical energy is also transferred to motion energy in organisms that move.) See the “Energy Science Library and Web Links” section on pages 42–49 and visit www.sciencecompanion.com/links for a list of suggested books and web sites to support this inquiry.

Friction Produces Heat Energy1. Have students observe the heat that is produced when moving

parts rub against each other and discuss the transfers of heat that take place:

a. Tell them to rub their hands back and forth against each other. What is happening to their hands?

b. Direct them to rub together two sheets of sandpaper in a circular motion, without stopping, for several minutes. Have them compare how the sandpaper feels before and after rubbing. What has changed?

2. To help children understand the significance of friction, discuss why a roller coaster seems to “run out of energy.” Post a picture of a roller coaster (or have students build one!) to further the discussion. Consider questions such as these:

• Why does a roller coaster start at the highest hill?

• Why do the hills of a roller coaster get smaller and smaller?

• What causes the roller coaster to slow down?

• Do the cars “rub” against the air?

• Do the wheels “rub” against the track?

• Based on the earlier hand-rubbing and sandpaper rubbing activities, what should happen to the air and tracks as they “rub against” the cars?

• Would anyone be able to see if the air and the tracks were getting hotter? Could this explain why many things seem to run out of energy?

• Does the roller coaster really “run out of energy” or use energy up, or has its energy just been transferred to less useful forms?

Extending the Lesson

Further Science Explorations

Energy Toys from ScratchProvide students with the materials and instructions for several handmade toys, such as whirligigs, button spinners, and tops. See www.sciencecompanion.com/links for links to web sites that offer simple directions for making these and other toys.

Chemical Energy Fun• Demonstrate the chemical-to-heat energy transfer that occurs

when baking yeast and hydrogen peroxide are mixed:

safeTy NoTe: The chemical component (hydrogen peroxide) used in this extension is a common household item and is not hazardous if used with care. Please check with your supervisor about OSHA or state regulations regarding laboratory practice and chemical storage. Use caution and have the children wear goggles and protective gloves when working with hydrogen peroxide.

a. Pour two ounces of hydrogen peroxide in a medium-sized jar.

b. Place a thermometer into the jar to take an initial temperature reading.

c. Add a teaspoon of granular baking yeast to the jar and provide a continuous report to the class of the change (rapid increase) in temperature.

d. Discuss the increase in temperature. Has the energy in the jar changed forms? How can they tell? (Students should recognize that some of the chemical energy of the yeast and hydrogen peroxide has been transferred to heat energy; this accounts for the increase in temperature.)

e. Talk about anything else the children may notice. What other signs indicate that changes have occurred in the jar? (The mixture will immediately begin to bubble and rise up in the jar.)

• Explore a chemical-to-motion energy transfer that’s a blast! Take students outdoors to make and launch pop rockets. Visit www.sciencecompanion.com/links for links to web sites that offer simple directions for making pop rockets using water, Alka-Seltzer®, and a film canister.

safeTy NoTe: Make sure that students wear safety goggles during this pop rocket activity.

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Energy Transfers and the Food Chain

nature’s recyclers connectionExploring food chains with a focus on energy is an ideal way to build upon a key concept from the Science Companion Level 4 Nature’s Recyclers Unit—the recycling of matter through ecosystems. While the total amount of matter at each level of a food chain remains constant, the energy available at each level diminishes as some chemical energy is transformed into forms such as heat and motion that are no longer available to the next level.

Provide opportunities for students to trace the transfer of chemical energy through the food chain. Focus on the decrease in available chemical energy at each stage in a food chain. Discuss some of the energy transfers that account for this decrease. (Living organisms generate heat—a chemical-to-heat energy transfer. This heat energy is in turn transferred to the organisms’ surroundings, making it unavailable to the next level of the food chain. Some chemical energy is also transferred to motion energy in organisms that move.) See the “Energy Science Library and Web Links” section on pages 42–49 and visit www.sciencecompanion.com/links for a list of suggested books and web sites to support this inquiry.

Friction Produces Heat Energy1. Have students observe the heat that is produced when moving

parts rub against each other and discuss the transfers of heat that take place:

a. Tell them to rub their hands back and forth against each other. What is happening to their hands?

b. Direct them to rub together two sheets of sandpaper in a circular motion, without stopping, for several minutes. Have them compare how the sandpaper feels before and after rubbing. What has changed?

2. To help children understand the significance of friction, discuss why a roller coaster seems to “run out of energy.” Post a picture of a roller coaster (or have students build one!) to further the discussion. Consider questions such as these:

• Why does a roller coaster start at the highest hill?

• Why do the hills of a roller coaster get smaller and smaller?

• What causes the roller coaster to slow down?

• Do the cars “rub” against the air?

• Do the wheels “rub” against the track?

• Based on the earlier hand-rubbing and sandpaper rubbing activities, what should happen to the air and tracks as they “rub against” the cars?

• Would anyone be able to see if the air and the tracks were getting hotter? Could this explain why many things seem to run out of energy?

• Does the roller coaster really “run out of energy” or use energy up, or has its energy just been transferred to less useful forms?

Extending the Lesson

Further Science Explorations

Energy Toys from ScratchProvide students with the materials and instructions for several handmade toys, such as whirligigs, button spinners, and tops. See www.sciencecompanion.com/links for links to web sites that offer simple directions for making these and other toys.

Chemical Energy Fun• Demonstrate the chemical-to-heat energy transfer that occurs

when baking yeast and hydrogen peroxide are mixed:

safeTy NoTe: The chemical component (hydrogen peroxide) used in this extension is a common household item and is not hazardous if used with care. Please check with your supervisor about OSHA or state regulations regarding laboratory practice and chemical storage. Use caution and have the children wear goggles and protective gloves when working with hydrogen peroxide.

a. Pour two ounces of hydrogen peroxide in a medium-sized jar.

b. Place a thermometer into the jar to take an initial temperature reading.

c. Add a teaspoon of granular baking yeast to the jar and provide a continuous report to the class of the change (rapid increase) in temperature.

d. Discuss the increase in temperature. Has the energy in the jar changed forms? How can they tell? (Students should recognize that some of the chemical energy of the yeast and hydrogen peroxide has been transferred to heat energy; this accounts for the increase in temperature.)

e. Talk about anything else the children may notice. What other signs indicate that changes have occurred in the jar? (The mixture will immediately begin to bubble and rise up in the jar.)

• Explore a chemical-to-motion energy transfer that’s a blast! Take students outdoors to make and launch pop rockets. Visit www.sciencecompanion.com/links for links to web sites that offer simple directions for making pop rockets using water, Alka-Seltzer®, and a film canister.

safeTy NoTe: Make sure that students wear safety goggles during this pop rocket activity.

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Language Arts ExtensionHave children interview an older family member or neighbor to find out about the mechanical toys they played with as a child. What energy forms were used to make their toys move? What energy forms are commonly used today to make toys run? Consider organizing the students’ findings into a Venn diagram, comparing and contrasting the toys of “Then” and “Now.”

Social Studies ExtensionResearch toys of the 19th century. See the “Energy Science Library and Web Links” section on pages 42–49 and visit www.sciencecompanion.com/links for a list of suggested books and web sites to support this research.

Art Extensions• Have students create flip-books depicting an energy transfer

such as a sailboat propelled by the wind, a chain of dominoes falling, or a baseball bat hitting a ball.

• Reinforce the concept of wind energy by having students create their own kite designs. Submit students’ designs to the Franklin Institute’s Current Creations Archive. Visit www.sciencecompanion.com/links for further details.

Planning Ahead

For Lesson 4Give yourself enough time in advance of Lesson 4 to collect the materials you’ll need, particularly the large, shallow basin for class demonstrations of the boats and the nine smaller basins individual groups will be using to test their boats. Consider sending home the Teacher Master “Request for Materials” to help you get everything you need to conduct this lesson.

For Lesson �Collect empty 2-liter soda bottles. You will need one per group during Session 1.

| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN

Teacher DirectionsSetting Up the Energy Stations

MaterialsItem Quantity notes

ExploraGear

Ball 1 (3 extra) To demonstrate the transfer of energy.

Chenille wire 1 To make magic bracelet.

Clamp lamp and bulb (optional) 2 To light magic bracelet or radiometer.

Dominoes 1 set To demonstrate the transfer of energy.

Energy ball 1 To demonstrate the transfer of energy.

Hand-held electrical generator 1 To demonstrate the transfer of energy.

Pop-up toy 4 To demonstrate the transfer of energy.

Radiometer 1 To demonstrate the transfer of energy.

Solar energy beads 1 package To make magic bracelet.

Sparking-wheel toy 1 (3 extra) To demonstrate the transfer of energy.

Spinning tops with lights 2 To demonstrate the transfer of energy.

Toy car, pull-back type (optional) 1 (2 extra) To demonstrate the transfer of energy.

Classroom Supplies

Gift box top, large 1 To contain spinning top.

Light source (flashlight, lamp, or sunlight)

1 To power radiometer.

Paper bag, opaque, medium 1 To shield energy-bead bracelet from light. A lunch bag or gift bag works well.

Screwdriver, small, Phillips head 1 To dismantle one of the spinning tops.

Tape 1 roll To tape shut the energy ball.

Preparing the Toys1. Make the magic bracelet for Energy Station 9. Locate the energy beads and chenille wire provided in the

ExploraGear. Thread the beads through the chenille wire and twist together the ends to create a bracelet large enough for children to slip their hands through.

2. Take apart one of the spinning tops using a Phillips head screwdriver. Save all the pieces so students can see and manipulate the top’s working parts at station 6. Leave it unassembled throughout the exploration.

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Language Arts ExtensionHave children interview an older family member or neighbor to find out about the mechanical toys they played with as a child. What energy forms were used to make their toys move? What energy forms are commonly used today to make toys run? Consider organizing the students’ findings into a Venn diagram, comparing and contrasting the toys of “Then” and “Now.”

Social Studies ExtensionResearch toys of the 19th century. See the “Energy Science Library and Web Links” section on pages 42–49 and visit www.sciencecompanion.com/links for a list of suggested books and web sites to support this research.

Art Extensions• Have students create flip-books depicting an energy transfer

such as a sailboat propelled by the wind, a chain of dominoes falling, or a baseball bat hitting a ball.

• Reinforce the concept of wind energy by having students create their own kite designs. Submit students’ designs to the Franklin Institute’s Current Creations Archive. Visit www.sciencecompanion.com/links for further details.

Planning Ahead

For Lesson 4Give yourself enough time in advance of Lesson 4 to collect the materials you’ll need, particularly the large, shallow basin for class demonstrations of the boats and the nine smaller basins individual groups will be using to test their boats. Consider sending home the Teacher Master “Request for Materials” to help you get everything you need to conduct this lesson.

For Lesson �Collect empty 2-liter soda bottles. You will need one per group during Session 1.

ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN |

Teacher DirectionsSetting Up the Energy Stations

MaterialsItem Quantity notes

ExploraGear

Ball 1 (3 extra) To demonstrate the transfer of energy.

Chenille wire 1 To make magic bracelet.

Clamp lamp and bulb (optional) 2 To light magic bracelet or radiometer.

Dominoes 1 set To demonstrate the transfer of energy.

Energy ball 1 To demonstrate the transfer of energy.

Hand-held electrical generator 1 To demonstrate the transfer of energy.

Pop-up toy 4 To demonstrate the transfer of energy.

Radiometer 1 To demonstrate the transfer of energy.

Solar energy beads 1 package To make magic bracelet.

Sparking-wheel toy 1 (3 extra) To demonstrate the transfer of energy.

Spinning tops with lights 2 To demonstrate the transfer of energy.

Toy car, pull-back type (optional) 1 (2 extra) To demonstrate the transfer of energy.

Classroom Supplies

Gift box top, large 1 To contain spinning top.

Light source (flashlight, lamp, or sunlight)

1 To power radiometer.

Paper bag, opaque, medium 1 To shield energy-bead bracelet from light. A lunch bag or gift bag works well.

Screwdriver, small, Phillips head 1 To dismantle one of the spinning tops.

Tape 1 roll To tape shut the energy ball.

Preparing the Toys1. Make the magic bracelet for Energy Station 9. Locate the energy beads and chenille wire provided in the

ExploraGear. Thread the beads through the chenille wire and twist together the ends to create a bracelet large enough for children to slip their hands through.

2. Take apart one of the spinning tops using a Phillips head screwdriver. Save all the pieces so students can see and manipulate the top’s working parts at station 6. Leave it unassembled throughout the exploration.

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Setting Up the StationsSet up the nine energy stations for Session 2 as follows:

• Stagger stations throughout the room, using student desk tops, available counter space, and even open floor space. Any space will do as long as there is enough room for small groups to gather around each toy and operate it.

• Place each toy, along with its directions and any of the additional supplies described in the table below, at the appropriate station.

• After the stations are set up, conduct a trial run through each to make sure that the toys are operating properly. Troubleshoot problems as necessary and feel free to make replacements to ensure student success. (For example, you can trade the pull-back car for a problematic toy.)

Teacher NoTe: The basic energy transfers the children are likely to notice at each station are listed in the following table. While these transfers may be the most obvious, students may notice and include others in their energy maps as well, such as the background noise produced by several of the toys (sound energy).

Station number

Type of Toy Additional Supplies/notes Energy Transfers (Most Evident)

1 Pop-up toy Four pop-up toys are provided. Test these out and select one that pops up consistently and in a reasonable amount of time.

Motion to elastic to motion

2 Dominoes Motion to motion to gravitational to motion…

3 Sparking-wheel

Four sparking wheels are provided.Only put out one at a time that consistently generates sparks when operated. Make sure the students follow the directions for the sparking wheel. If used improperly, the wheel will quickly break.

Motion to heat and light

4 Energy ball Tape the energy ball shut before use.

Chemical (battery) to electrical to light and sound

5 Hand-held electrical generator

Make sure light bulb is inserted and working.

Motion to electrical to light; also motion to sound

6 Spinning tops with light (one intact, one taken apart)

Place the intact spinning top in a large gift box lid and the disassembled top off to the side.

Motion to elastic to motion and light

7 Radiometer Set up this station in sunlight or under the clamp lamp. Mark the station with a “Fragile, Handle with Care” sign.

Light to heat to motion

8 Ball Set up this station on an open area of the floor so that students can bounce the ball.

Gravitational to motion to elastic to motion

Explaining How Some Toys WorkOffer the following explanations for the more complex toys if students want to know more about how they work. You don’t need to present this information to the entire class, unless they are all interested.

• Sparking Wheel—Pumping the wheel creates friction. The friction breaks off tiny pieces of a flammable metal alloy. The friction also generates enough heat (motion to heat) to ignite these metal chips, creating sparks. The sparks are only visible momentarily since they quickly cool down. The sparks may lead some students to conclude that the energy transfer includes electrical energy. You can dispel this notion at your discretion.

• Energy Ball—Inside the energy ball are two batteries connected to a light and sound system. When both metal strips (electrodes) are touched, the electric circuit is completed, allowing electrons to flow through the batteries, the person holding the ball, and the light and sound systems. This flow of electricity makes the ball light up and hum.

• Hand-held Electrical Generator—When a bundle of copper wire (or any other conductor) is moved through a magnetic field, electrical current will start to flow along the wire. Peek through the slots in the metal cylinder inside the generator toy; you can see the copper wire bundles that rotate when the handle is turned. The magnets cannot be seen.

| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN

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Setting Up the StationsSet up the nine energy stations for Session 2 as follows:

• Stagger stations throughout the room, using student desk tops, available counter space, and even open floor space. Any space will do as long as there is enough room for small groups to gather around each toy and operate it.

• Place each toy, along with its directions and any of the additional supplies described in the table below, at the appropriate station.

• After the stations are set up, conduct a trial run through each to make sure that the toys are operating properly. Troubleshoot problems as necessary and feel free to make replacements to ensure student success. (For example, you can trade the pull-back car for a problematic toy.)

Teacher NoTe: The basic energy transfers the children are likely to notice at each station are listed in the following table. While these transfers may be the most obvious, students may notice and include others in their energy maps as well, such as the background noise produced by several of the toys (sound energy).

Station number

Type of Toy Additional Supplies/notes Energy Transfers (Most Evident)

1 Pop-up toy Four pop-up toys are provided. Test these out and select one that pops up consistently and in a reasonable amount of time.

Motion to elastic to motion

2 Dominoes Motion to motion to gravitational to motion…

3 Sparking-wheel

Four sparking wheels are provided.Only put out one at a time that consistently generates sparks when operated. Make sure the students follow the directions for the sparking wheel. If used improperly, the wheel will quickly break.

Motion to heat and light

4 Energy ball Tape the energy ball shut before use.

Chemical (battery) to electrical to light and sound

5 Hand-held electrical generator

Make sure light bulb is inserted and working.

Motion to electrical to light; also motion to sound

6 Spinning tops with light (one intact, one taken apart)

Place the intact spinning top in a large gift box lid and the disassembled top off to the side.

Motion to elastic to motion and light

7 Radiometer Set up this station in sunlight or under the clamp lamp. Mark the station with a “Fragile, Handle with Care” sign.

Light to heat to motion

8 Ball Set up this station on an open area of the floor so that students can bounce the ball.

Gravitational to motion to elastic to motion

Station number

Type of Toy Additional Supplies/notes Energy Transfers (Most Evident)

9 Magic bracelet Set up this station in an area with ample sunlight. If sunlight is inadequate on the day you conduct this portion of the lesson, set up this station with a clamp lamp fitted with a compact fluorescent bulb. Make sure to turn the lamp on at least five minutes before students visit this station so that the bulb will be adequately warmed up. Place the pre-assembled bracelet in an opaque paper bag.

Light to chemical

Optional replacement

Pull-back toy car

Motion to elastic (spring) to motion

Explaining How Some Toys WorkOffer the following explanations for the more complex toys if students want to know more about how they work. You don’t need to present this information to the entire class, unless they are all interested.

• Sparking Wheel—Pumping the wheel creates friction. The friction breaks off tiny pieces of a flammable metal alloy. The friction also generates enough heat (motion to heat) to ignite these metal chips, creating sparks. The sparks are only visible momentarily since they quickly cool down. The sparks may lead some students to conclude that the energy transfer includes electrical energy. You can dispel this notion at your discretion.

• Energy Ball—Inside the energy ball are two batteries connected to a light and sound system. When both metal strips (electrodes) are touched, the electric circuit is completed, allowing electrons to flow through the batteries, the person holding the ball, and the light and sound systems. This flow of electricity makes the ball light up and hum.

• Hand-held Electrical Generator—When a bundle of copper wire (or any other conductor) is moved through a magnetic field, electrical current will start to flow along the wire. Peek through the slots in the metal cylinder inside the generator toy; you can see the copper wire bundles that rotate when the handle is turned. The magnets cannot be seen.

NoTes

ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN |

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NoTes

| ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN��

• Spinning Top—There is a small metal ball inside the top that acts as a switch. When the top spins, the ball is forced outward, completing the electrical circuit that turns the light on.

light connectionBuild on students’ understanding of sunlight from the Science Companion Level 3 Light Unit by giving them the opportunity to test and discover that solar beads do not change color when exposed to visible light alone (indoor lighting) but do change when exposed to sunlight, suggesting that sunlight contains forms of radiation beyond just visible light.

• Radiometer—The sealed glass bulb maintains a partial vacuum, to reduce air friction. When light hits the metal vanes it reflects off the white sides, but is absorbed as heat energy on the black sides. Air molecules flow around the edges of each vane, from the cooler white side toward the warmer black side, causing the top to spin.

• Magic Bracelet—The beads in this bracelet are solar energy beads. Each bead contains a type of pigment that changes color when exposed to ultraviolet light. Sunlight and the light produced by compact fluorescent bulbs contain both ultraviolet and visible light; the ultraviolet light they contain activates the beads. Visible light alone (such as that provided by typical incandescent lighting) will not change the color of the beads.

Overhead Transparency: “Mapping Energy Transfers” Science Notebook page 5–13

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��ENERGY | lEssoN 3 | ENERGY TRaNsfERs: how ENERGY makEs ThiNGs haPPEN |

• Spinning Top—There is a small metal ball inside the top that acts as a switch. When the top spins, the ball is forced outward, completing the electrical circuit that turns the light on.

light connectionBuild on students’ understanding of sunlight from the Science Companion Level 3 Light Unit by giving them the opportunity to test and discover that solar beads do not change color when exposed to visible light alone (indoor lighting) but do change when exposed to sunlight, suggesting that sunlight contains forms of radiation beyond just visible light.

• Radiometer—The sealed glass bulb maintains a partial vacuum, to reduce air friction. When light hits the metal vanes it reflects off the white sides, but is absorbed as heat energy on the black sides. Air molecules flow around the edges of each vane, from the cooler white side toward the warmer black side, causing the top to spin.

• Magic Bracelet—The beads in this bracelet are solar energy beads. Each bead contains a type of pigment that changes color when exposed to ultraviolet light. Sunlight and the light produced by compact fluorescent bulbs contain both ultraviolet and visible light; the ultraviolet light they contain activates the beads. Visible light alone (such as that provided by typical incandescent lighting) will not change the color of the beads.

Teacher Master 3, Assessment 1 Teacher Masters 15–16

Teacher Masters 17–18 Teacher Master 41, Family Link

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Teacher Background Information

This section provides a detailed overview of energy—its significance in the world around us; the forms it takes; how it transfers from one object to another; how easily it passes through different materials; and how it is harnessed in everyday machines. This introduction is intended to give you background information you may need as you teach the unit; however, it is not necessary to master or present all the content that is offered here. The Key Notes section of each lesson indicates which portion to review prior to teaching the lesson. A preliminary read-through before teaching the unit—to get the big picture—followed by more focused readings before each lesson should help you guide the children in their discoveries about the role of energy in the world around them.

Introduction

Energy: A Unifying ConceptEnergy is integral to our understanding of the world around us. It is at the root of all change. Every time something happens, energy is involved. It is the energy in gasoline that makes an automobile run; the energy added to water that makes it boil; the energy in food that allows us to move and grow; the energy of an exploding stick of dynamite that blasts through solid rock; the energy in the sun’s rays that drives weather and life itself; and the energy of moving water, air, sand, and ice that reshapes the surface of the earth.

What Is Energy?Energy is something we understand through experience. We can feel, see, and hear the energy of a thunderstorm. We know what foods to eat when we need a boost of energy. We are amused by the boundless energy of a puppy. We realize that our garden needs the sun’s energy to grow. Intuitively, we understand that energy makes things happen. Doing work is one way to “make things happen” so it is not surprising that the word energy is derived from the Greek word energeia, meaning “at work.”

Scientific definitions for energy also incorporate the idea of work. One common definition for energy is “the ability to perform

work.” While this definition is meaningful to scientists, it can be problematic for students. For scientists, the concept of “work” has a special meaning—“force applied over a distance.” For students, however, many of the things that energy “makes happen,” such as the soaring of a soccer ball, the flash of a bolt of lightning, or the bounce of a trampoline, are not likely to be considered work.

A common misconception held by students is that energy is a “thing” rather than a property of something. Properties, such as energy, are inherently harder to explain and grasp. Energy has no mass, shape, taste, or odor but it can be measured. It can be felt but not touched. Nonetheless, we can recognize, appreciate, explore, and understand energy without a formal definition. In this unit, children will develop their own “working definition” of energy as they explore the role that energy plays in the world around them.

Forms of EnergyEnergy is best described to children in terms of how they experience it in everyday life. While physicists employ a much stricter and more complex standard for distinguishing energy forms, this unit introduces energy in terms of forms that are accessible to students. Don’t be concerned by the variations you encounter in how energy forms are defined and presented in resource books and videos. In this unit, designed specifically for 5th graders, keeping the categories of energy forms simple and recognizable will help students focus on energy’s importance in the world around them.

Two Major Kinds of Energy: Energy in Action and Stored EnergyOne basic way to think about energy is to categorize it into two major forms: energy in action and stored energy (energy not yet in use).

Energy in action is energy in the “act” of bringing about change. Where there is action there is motion. To account for the many different ways that motion is manifested, a variety of energy forms can be considered forms of energy in action.

Stored energy, also referred to as potential energy, is the energy possessed by something but not yet bringing about change. Stored energy results from the position of an object and the forces which are acting on it. Like energy in action, stored or potential energy can be considered to exist in several forms.

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Teacher Background Information

This section provides a detailed overview of energy—its significance in the world around us; the forms it takes; how it transfers from one object to another; how easily it passes through different materials; and how it is harnessed in everyday machines. This introduction is intended to give you background information you may need as you teach the unit; however, it is not necessary to master or present all the content that is offered here. The Key Notes section of each lesson indicates which portion to review prior to teaching the lesson. A preliminary read-through before teaching the unit—to get the big picture—followed by more focused readings before each lesson should help you guide the children in their discoveries about the role of energy in the world around them.

Introduction

Energy: A Unifying ConceptEnergy is integral to our understanding of the world around us. It is at the root of all change. Every time something happens, energy is involved. It is the energy in gasoline that makes an automobile run; the energy added to water that makes it boil; the energy in food that allows us to move and grow; the energy of an exploding stick of dynamite that blasts through solid rock; the energy in the sun’s rays that drives weather and life itself; and the energy of moving water, air, sand, and ice that reshapes the surface of the earth.

What Is Energy?Energy is something we understand through experience. We can feel, see, and hear the energy of a thunderstorm. We know what foods to eat when we need a boost of energy. We are amused by the boundless energy of a puppy. We realize that our garden needs the sun’s energy to grow. Intuitively, we understand that energy makes things happen. Doing work is one way to “make things happen” so it is not surprising that the word energy is derived from the Greek word energeia, meaning “at work.”

Scientific definitions for energy also incorporate the idea of work. One common definition for energy is “the ability to perform

work.” While this definition is meaningful to scientists, it can be problematic for students. For scientists, the concept of “work” has a special meaning—“force applied over a distance.” For students, however, many of the things that energy “makes happen,” such as the soaring of a soccer ball, the flash of a bolt of lightning, or the bounce of a trampoline, are not likely to be considered work.

A common misconception held by students is that energy is a “thing” rather than a property of something. Properties, such as energy, are inherently harder to explain and grasp. Energy has no mass, shape, taste, or odor but it can be measured. It can be felt but not touched. Nonetheless, we can recognize, appreciate, explore, and understand energy without a formal definition. In this unit, children will develop their own “working definition” of energy as they explore the role that energy plays in the world around them.

Forms of EnergyEnergy is best described to children in terms of how they experience it in everyday life. While physicists employ a much stricter and more complex standard for distinguishing energy forms, this unit introduces energy in terms of forms that are accessible to students. Don’t be concerned by the variations you encounter in how energy forms are defined and presented in resource books and videos. In this unit, designed specifically for 5th graders, keeping the categories of energy forms simple and recognizable will help students focus on energy’s importance in the world around them.

Two Major Kinds of Energy: Energy in Action and Stored EnergyOne basic way to think about energy is to categorize it into two major forms: energy in action and stored energy (energy not yet in use).

Energy in action is energy in the “act” of bringing about change. Where there is action there is motion. To account for the many different ways that motion is manifested, a variety of energy forms can be considered forms of energy in action.

Stored energy, also referred to as potential energy, is the energy possessed by something but not yet bringing about change. Stored energy results from the position of an object and the forces which are acting on it. Like energy in action, stored or potential energy can be considered to exist in several forms.

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As discussed, these two major forms of energy—energy in action and stored energy—can each be broken down into several representative energy forms. The table below shows the two major categories and their representative energy forms.

Energy in Action Stored EnergyMotion energy Chemical (potential) energy

Heat energy Elastic (potential) energy

Light energy Gravitational (potential) energy

Electrical energy Nuclear energy

Sound energy

While “energy in action” and “stored energy” are used in the introductory and final lessons as “umbrellas” for students to group examples of energy under, the children are not expected to accurately specify each form as energy in action or stored energy. At this level, the children do not have the background necessary to understand why certain forms (particularly electrical, heat, sound, and light energy) are representative of one category or another. However, in this teacher’s introduction, we have categorized each form of energy in this way so you can relate the material to other sources, and have this broader understanding as you teach.

The frequently used terms “kinetic energy” and “potential energy” are not used in the lessons though you are likely to encounter them in other books and resources about energy. Kinetic energy, however, should technically not be applied to all forms of energy associated with motion. It is exclusively the energy of motion of matter (objects with mass or weight). Several of the energy forms presented under “Energy in Action” involve the movement of “mass-less” entities, such as waves and fields, and cannot be accurately categorized as kinetic energy. Furthermore, chemical energy and nuclear energy involve behavior of things at the atomic level and cannot be described by the usual concepts of kinetic and potential energy.

Energy in Action

Motion Energy

common misconceptionsStudents usually understand how moving things are energized and how their own bodies have energy. They have a more difficult time recognizing more abstract forms of energy, such as light, electricity, and elastic energy.

Motion energy, often referred to as kinetic energy, is the energy present in moving objects or materials, such as the wind or falling water. Motion energy is the most easily recognizable form of energy. When you see a speeding car, a soaring baseball, a rushing river, or a towering twister, the energy they possess is unmistakable. These examples embody change—energy is clearly at work.

We depend on motion energy to get us from place to place, chew our food, drive nails into walls, and power windmills and water turbines.

Heat Energy

The terms “heat,” “heat energy,” and “thermal energy” are synonymous. As you teach, whenever possible, reinforce that heat is energy to help dispel the common misconception that heat is a thing rather than a property of a substance. Using the term “heat energy” may help make this distinction but students should be aware that the term “heat,” so widely used in everyday life, also refers to “heat energy.”

For the students we define “heat energy” as the energy which an object has as a result of its temperature. At a more sophisticated level, heat, also known as thermal energy, is a consequence of motion. In this case, the particles moving are the minute atoms and molecules found within all substances. The faster these particles move the more heat energy a substance possesses.

Since the students may not know about atoms and molecules or the connection between their motion and heat, they are unlikely to associate heat energy with motion. For them, heat energy will be just a form of energy associated with an object’s temperature.

We depend on heat energy to cook our food, warm our homes and dry our clothes. In engines (gas, diesel, or steam) heat energy produced by burning fuels is transferred into energy of motion. Heat energy is also used in many power plants to generate electricity.

Students may confuse the terms heat energy and temperature. Whenever possible, reinforce to children that the heat energy of an object is not the same thing as its temperature. The amount of heat energy an object possesses depends not only on temperature—a measure of how hot or cold something is—but also on the mass of the object and on the type of matter from which it is formed. It is clear, for example, that a bathtub of water at 35oC (95oF) holds more heat energy than a glass of water at the same temperature. Comparing, or asking children to compare, how much heat energy would have to be added to a cold glass of water and a bathtub full of cold water to allow each to reach a temperature of 35oC may help to clarify this point.

One common source of heat energy is friction—the resistance that occurs whenever two substances rub against each other. While the heat energy resulting from friction is desirable when you are rubbing your hands together to stay warm, it is less desirable when the moving parts of your car’s engine heat up.

| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN

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As discussed, these two major forms of energy—energy in action and stored energy—can each be broken down into several representative energy forms. The table below shows the two major categories and their representative energy forms.

Energy in Action Stored EnergyMotion energy Chemical (potential) energy

Heat energy Elastic (potential) energy

Light energy Gravitational (potential) energy

Electrical energy Nuclear energy

Sound energy

While “energy in action” and “stored energy” are used in the introductory and final lessons as “umbrellas” for students to group examples of energy under, the children are not expected to accurately specify each form as energy in action or stored energy. At this level, the children do not have the background necessary to understand why certain forms (particularly electrical, heat, sound, and light energy) are representative of one category or another. However, in this teacher’s introduction, we have categorized each form of energy in this way so you can relate the material to other sources, and have this broader understanding as you teach.

The frequently used terms “kinetic energy” and “potential energy” are not used in the lessons though you are likely to encounter them in other books and resources about energy. Kinetic energy, however, should technically not be applied to all forms of energy associated with motion. It is exclusively the energy of motion of matter (objects with mass or weight). Several of the energy forms presented under “Energy in Action” involve the movement of “mass-less” entities, such as waves and fields, and cannot be accurately categorized as kinetic energy. Furthermore, chemical energy and nuclear energy involve behavior of things at the atomic level and cannot be described by the usual concepts of kinetic and potential energy.

Energy in Action

Motion Energy

common misconceptionsStudents usually understand how moving things are energized and how their own bodies have energy. They have a more difficult time recognizing more abstract forms of energy, such as light, electricity, and elastic energy.

Motion energy, often referred to as kinetic energy, is the energy present in moving objects or materials, such as the wind or falling water. Motion energy is the most easily recognizable form of energy. When you see a speeding car, a soaring baseball, a rushing river, or a towering twister, the energy they possess is unmistakable. These examples embody change—energy is clearly at work.

We depend on motion energy to get us from place to place, chew our food, drive nails into walls, and power windmills and water turbines.

Heat Energy

The terms “heat,” “heat energy,” and “thermal energy” are synonymous. As you teach, whenever possible, reinforce that heat is energy to help dispel the common misconception that heat is a thing rather than a property of a substance. Using the term “heat energy” may help make this distinction but students should be aware that the term “heat,” so widely used in everyday life, also refers to “heat energy.”

For the students we define “heat energy” as the energy which an object has as a result of its temperature. At a more sophisticated level, heat, also known as thermal energy, is a consequence of motion. In this case, the particles moving are the minute atoms and molecules found within all substances. The faster these particles move the more heat energy a substance possesses.

Since the students may not know about atoms and molecules or the connection between their motion and heat, they are unlikely to associate heat energy with motion. For them, heat energy will be just a form of energy associated with an object’s temperature.

We depend on heat energy to cook our food, warm our homes and dry our clothes. In engines (gas, diesel, or steam) heat energy produced by burning fuels is transferred into energy of motion. Heat energy is also used in many power plants to generate electricity.

Students may confuse the terms heat energy and temperature. Whenever possible, reinforce to children that the heat energy of an object is not the same thing as its temperature. The amount of heat energy an object possesses depends not only on temperature—a measure of how hot or cold something is—but also on the mass of the object and on the type of matter from which it is formed. It is clear, for example, that a bathtub of water at 35oC (95oF) holds more heat energy than a glass of water at the same temperature. Comparing, or asking children to compare, how much heat energy would have to be added to a cold glass of water and a bathtub full of cold water to allow each to reach a temperature of 35oC may help to clarify this point.

One common source of heat energy is friction—the resistance that occurs whenever two substances rub against each other. While the heat energy resulting from friction is desirable when you are rubbing your hands together to stay warm, it is less desirable when the moving parts of your car’s engine heat up.

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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Light EnergyFor the students we define “light energy” as the energy carried by light rays. On a more sophisticated level, light energy, also known as radiant energy, is the energy carried by electromagnetic waves—waves of energy traveling through matter or empty space.

While there are many types of electromagnetic waves—such as radio waves, microwaves, infrared waves, visible light, ultraviolet light, and x-rays—in this unit, light energy will primarily be equated with visible light, since that is the type most likely to be recognized by students. For example, the energy from the sun is referred to simply as light, even though it is actually a more complex combination of visible light, ultraviolet light, and infrared waves. If students in your class studied the Science Companion Level 3 Light Unit, you can refer back to what they learned about visible light in that unit and pursue discussions about other types of electromagnetic waves if the children bring them up.

All life ultimately depends on light energy. Plants harness the energy in sunlight to produce the food that supports all other living things, and sunlight warms the earth, maintaining surface temperatures that sustain life. The energy in light also makes photography possible and, when concentrated into special beams of light called lasers, is powerful enough to drill through metals and cut through tissue during surgery.

Electrical EnergyAll matter consists of minute building blocks called atoms. Atoms are composed of even smaller particles: a central nucleus consisting of protons (each with a positive electric charge) and neutrons (with a “neutral” charge—no electric charge), that is surrounded by a cloud of electrons (with negative electric charges). Electrically charged particles operate under an “opposites attract” principle.

Since (negatively charged) electrons are attracted to substances or regions with a net positive electric charge (which just means there are more protons than electrons in the region), they will naturally flow toward these regions when free to do so. In conductors—most metals, for example—some electrons are free to flow through the material because they are held loosely by their atoms. These flowing electrons possess electrical energy—they are capable of performing work and bringing about change.

Since the children have not yet learned that an electric current is a stream of moving particles, they are not likely to associate electrical energy with motion. At this stage, it’s sufficient for them to know that electrical energy is a type of energy associated with electric current.

The electricity (electrons flowing through a wire or another conductor) that powers household appliances—toasters, lights, refrigerators, computers, dishwashers, televisions, etc.—demonstrates the work that can be performed by electrical energy. A tree felled by a bolt of lightning is another familiar reminder of the power of electrical energy. In this case, there is so much electrical energy in the lightning bolt that it overcomes wood’s natural resistance to the flow of electrons (wood is usually an “insulator,” or non-conductor).

Children merely need to recognize examples of electrical energy in this unit. They should not be expected to know what is happening on a molecular level.

Sound EnergySound is carried through substances in waves of vibrating (back and forth moving) molecules. Where there is movement there is energy—the vibrating molecules that make up sound waves therefore possess energy. When sound waves hit the ear drum, they energize the eardrum which causes it to vibrate. The vibrating eardrum ultimately triggers messages to the brain (as vibrations pass from the eardrum to the bones of the middle ear to the fluid and tiny sensory hairs of the inner ear) that are the basis for hearing.

If students in your class studied the Science Companion Level 2 Sound Unit, you can refer back to what they learned about sound and vibrations in that unit.

Stored Energy

Chemical (Potential) EnergyChemical energy is the energy stored in chemical substances, such as fuel or food. All substances are made up of atoms and molecules. These atoms and molecules are connected to one another (held together) by attractive forces known as chemical bonds.

The attraction between positively and negatively charged particles is the “glue” that holds all matter together, allowing atoms to bind together to form molecules ranging from relatively simple molecules (such as pure metals) to very complex structures (such as proteins and DNA).

When the bonds between atoms and molecules rearrange, as they do during chemical reactions (such as burning), there is frequently a net release of energy. This potential for bond rearrangement and net energy release via chemical reactions is the basis for chemical energy. Even though it takes energy to break chemical bonds,

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Light EnergyFor the students we define “light energy” as the energy carried by light rays. On a more sophisticated level, light energy, also known as radiant energy, is the energy carried by electromagnetic waves—waves of energy traveling through matter or empty space.

While there are many types of electromagnetic waves—such as radio waves, microwaves, infrared waves, visible light, ultraviolet light, and x-rays—in this unit, light energy will primarily be equated with visible light, since that is the type most likely to be recognized by students. For example, the energy from the sun is referred to simply as light, even though it is actually a more complex combination of visible light, ultraviolet light, and infrared waves. If students in your class studied the Science Companion Level 3 Light Unit, you can refer back to what they learned about visible light in that unit and pursue discussions about other types of electromagnetic waves if the children bring them up.

All life ultimately depends on light energy. Plants harness the energy in sunlight to produce the food that supports all other living things, and sunlight warms the earth, maintaining surface temperatures that sustain life. The energy in light also makes photography possible and, when concentrated into special beams of light called lasers, is powerful enough to drill through metals and cut through tissue during surgery.

Electrical EnergyAll matter consists of minute building blocks called atoms. Atoms are composed of even smaller particles: a central nucleus consisting of protons (each with a positive electric charge) and neutrons (with a “neutral” charge—no electric charge), that is surrounded by a cloud of electrons (with negative electric charges). Electrically charged particles operate under an “opposites attract” principle.

Since (negatively charged) electrons are attracted to substances or regions with a net positive electric charge (which just means there are more protons than electrons in the region), they will naturally flow toward these regions when free to do so. In conductors—most metals, for example—some electrons are free to flow through the material because they are held loosely by their atoms. These flowing electrons possess electrical energy—they are capable of performing work and bringing about change.

Since the children have not yet learned that an electric current is a stream of moving particles, they are not likely to associate electrical energy with motion. At this stage, it’s sufficient for them to know that electrical energy is a type of energy associated with electric current.

The electricity (electrons flowing through a wire or another conductor) that powers household appliances—toasters, lights, refrigerators, computers, dishwashers, televisions, etc.—demonstrates the work that can be performed by electrical energy. A tree felled by a bolt of lightning is another familiar reminder of the power of electrical energy. In this case, there is so much electrical energy in the lightning bolt that it overcomes wood’s natural resistance to the flow of electrons (wood is usually an “insulator,” or non-conductor).

Children merely need to recognize examples of electrical energy in this unit. They should not be expected to know what is happening on a molecular level.

Sound EnergySound is carried through substances in waves of vibrating (back and forth moving) molecules. Where there is movement there is energy—the vibrating molecules that make up sound waves therefore possess energy. When sound waves hit the ear drum, they energize the eardrum which causes it to vibrate. The vibrating eardrum ultimately triggers messages to the brain (as vibrations pass from the eardrum to the bones of the middle ear to the fluid and tiny sensory hairs of the inner ear) that are the basis for hearing.

If students in your class studied the Science Companion Level 2 Sound Unit, you can refer back to what they learned about sound and vibrations in that unit.

Stored Energy

Chemical (Potential) EnergyChemical energy is the energy stored in chemical substances, such as fuel or food. All substances are made up of atoms and molecules. These atoms and molecules are connected to one another (held together) by attractive forces known as chemical bonds.

The attraction between positively and negatively charged particles is the “glue” that holds all matter together, allowing atoms to bind together to form molecules ranging from relatively simple molecules (such as pure metals) to very complex structures (such as proteins and DNA).

When the bonds between atoms and molecules rearrange, as they do during chemical reactions (such as burning), there is frequently a net release of energy. This potential for bond rearrangement and net energy release via chemical reactions is the basis for chemical energy. Even though it takes energy to break chemical bonds,

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if new, more stable (less energetic) bonds form, more energy is released than is used.

Substances, such as dynamite, made up of atoms and molecules bound together by high-energy, less stable bonds, are a rich source of chemical energy. As their high-energy bonds are broken and more stable, lower-energy bonds form, significant amounts of energy are freed up and released. Burning (combustion) is a familiar chemical reaction that results in the release of chemical energy. When the chemicals in materials such as wood “burn.” their chemical bonds rearrange—high-energy bonds (in the wood) are broken and more stable, lower-energy bonds (in the products of burning such as CO2 and H2O) form. The difference in energy between these low and high energy bonds accounts for the release of energy you feel when wood is burned.

common misconceptionStudents may find it strange to consider food a chemical, since—in general usage—a chemical may be something they are warned never to eat.

Petroleum, natural gas, coal, and propane are burned to release the stored chemical energy that powers our cars, planes, and trains, heats and cools our homes, and generates the electricity that keeps our lives “humming.” We depend on the chemical energy in food to allow our bodies to grow and function. We blast through mountains using the chemical energy in dynamite and harness the chemical energy in gunpowder to light up the skies on holidays.

Elastic (Potential) EnergyElastic energy is the energy stored when elastic materials are stretched or compressed. Materials that demonstrate elasticity, such as rubber bands and springs, can be deformed but naturally revert to their original shape when the force causing the deformation is removed. As the materials return to their original shape, the energy that was used to stretch or compress them is released and can be used to perform work (although some of the energy is released as heat).

Slingshots, bows and arrows, wind-up toys, bungee cords, winding clocks, and balloons demonstrate some of the ways that the energy of deformed (compressed or stretched) materials is stored and then used to produce motion or do work.

Gravitational (Potential) EnergyAll matter is attracted to other matter by the force of gravity. The more massive and closer one object is to another, the more gravitational force it exerts. On Earth, it is the planet itself—as a consequence of its massive size and proximity—that is the predominant source of gravitational attraction. Earth exerts a continuous pull on all objects within its domain or gravitational field. (In addition to Earth’s pull, all objects at or near Earth’s surface—by virtue of their mass—also exert gravitational pull on

each other. However, because the Earth is so massive relative to these objects, their gravitational pull is negligible.)

Energy is required to move an object against Earth’s gravitational pull. When you push a large boulder up a hill or throw a ball in the air, you use energy to move against Earth’s gravitational attraction. The energy expended to move the ball and boulder away from Earth’s center of gravity is now “stored” by virtue of the object’s new position relative to Earth’s gravitational field. Give the boulder a slight nudge and you will see its stored gravitational energy put to work clearing a path as it thunders down the hill. The heavier an object is and the higher it is raised, the more gravitational energy it possesses (and the more energy it took to get it there). A massive boulder teetering at the top of a hill has much more gravitational energy than a pebble poised at the same spot, and a ball raised to a height of 100 meters (109.4 yards) has more gravitational energy than it would have if it was raised to a height of only10 meters (10.94 yards).

Water behind a dam represents a huge “reservoir” of gravitational energy. Hydroelectric power plants capitalize on this potential energy, releasing the water behind a dam in controlled flows to spin huge turbines that produce electricity. Gravitational energy also gives raised hammers their extra “punch” and provides the “thrill” that people seek when they board a roller coaster.

Nuclear Energy

Students are not explicitly introduced to nuclear energy in this unit. If you live in an area supplied by a nuclear power plant or have students who are interested in nuclear energy, you may want to introduce the following information, in a simple form, to the class.

Nuclear energy is the energy stored in the dense central region of atoms known as the nucleus. It is released whenever heavy unstable nuclei (the plural form of nucleus) break down (fission) or whenever light nuclei combine (fusion). During fission and fusion a minute quantity of the atom’s mass is actually changed into a very large amount of energy. Einstein’s famous equation E = mc2, in which E stands for energy, m for mass, and c for the speed of light (about 300,000 kilometers per second or 186,000 miles per second) describes this phenomenon.

The energy from the sun that sustains life on Earth is based on the fusion of nuclei in the sun’s core and the subsequent release of nuclear energy. The controlled fission of uranium nuclei provides electricity at nuclear power plants and the uncontrolled chain-reaction fission of uranium and plutonium nuclei gives atomic bombs their destructive power.

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if new, more stable (less energetic) bonds form, more energy is released than is used.

Substances, such as dynamite, made up of atoms and molecules bound together by high-energy, less stable bonds, are a rich source of chemical energy. As their high-energy bonds are broken and more stable, lower-energy bonds form, significant amounts of energy are freed up and released. Burning (combustion) is a familiar chemical reaction that results in the release of chemical energy. When the chemicals in materials such as wood “burn.” their chemical bonds rearrange—high-energy bonds (in the wood) are broken and more stable, lower-energy bonds (in the products of burning such as CO2 and H2O) form. The difference in energy between these low and high energy bonds accounts for the release of energy you feel when wood is burned.

common misconceptionStudents may find it strange to consider food a chemical, since—in general usage—a chemical may be something they are warned never to eat.

Petroleum, natural gas, coal, and propane are burned to release the stored chemical energy that powers our cars, planes, and trains, heats and cools our homes, and generates the electricity that keeps our lives “humming.” We depend on the chemical energy in food to allow our bodies to grow and function. We blast through mountains using the chemical energy in dynamite and harness the chemical energy in gunpowder to light up the skies on holidays.

Elastic (Potential) EnergyElastic energy is the energy stored when elastic materials are stretched or compressed. Materials that demonstrate elasticity, such as rubber bands and springs, can be deformed but naturally revert to their original shape when the force causing the deformation is removed. As the materials return to their original shape, the energy that was used to stretch or compress them is released and can be used to perform work (although some of the energy is released as heat).

Slingshots, bows and arrows, wind-up toys, bungee cords, winding clocks, and balloons demonstrate some of the ways that the energy of deformed (compressed or stretched) materials is stored and then used to produce motion or do work.

Gravitational (Potential) EnergyAll matter is attracted to other matter by the force of gravity. The more massive and closer one object is to another, the more gravitational force it exerts. On Earth, it is the planet itself—as a consequence of its massive size and proximity—that is the predominant source of gravitational attraction. Earth exerts a continuous pull on all objects within its domain or gravitational field. (In addition to Earth’s pull, all objects at or near Earth’s surface—by virtue of their mass—also exert gravitational pull on

each other. However, because the Earth is so massive relative to these objects, their gravitational pull is negligible.)

Energy is required to move an object against Earth’s gravitational pull. When you push a large boulder up a hill or throw a ball in the air, you use energy to move against Earth’s gravitational attraction. The energy expended to move the ball and boulder away from Earth’s center of gravity is now “stored” by virtue of the object’s new position relative to Earth’s gravitational field. Give the boulder a slight nudge and you will see its stored gravitational energy put to work clearing a path as it thunders down the hill. The heavier an object is and the higher it is raised, the more gravitational energy it possesses (and the more energy it took to get it there). A massive boulder teetering at the top of a hill has much more gravitational energy than a pebble poised at the same spot, and a ball raised to a height of 100 meters (109.4 yards) has more gravitational energy than it would have if it was raised to a height of only10 meters (10.94 yards).

Water behind a dam represents a huge “reservoir” of gravitational energy. Hydroelectric power plants capitalize on this potential energy, releasing the water behind a dam in controlled flows to spin huge turbines that produce electricity. Gravitational energy also gives raised hammers their extra “punch” and provides the “thrill” that people seek when they board a roller coaster.

Nuclear Energy

Students are not explicitly introduced to nuclear energy in this unit. If you live in an area supplied by a nuclear power plant or have students who are interested in nuclear energy, you may want to introduce the following information, in a simple form, to the class.

Nuclear energy is the energy stored in the dense central region of atoms known as the nucleus. It is released whenever heavy unstable nuclei (the plural form of nucleus) break down (fission) or whenever light nuclei combine (fusion). During fission and fusion a minute quantity of the atom’s mass is actually changed into a very large amount of energy. Einstein’s famous equation E = mc2, in which E stands for energy, m for mass, and c for the speed of light (about 300,000 kilometers per second or 186,000 miles per second) describes this phenomenon.

The energy from the sun that sustains life on Earth is based on the fusion of nuclei in the sun’s core and the subsequent release of nuclear energy. The controlled fission of uranium nuclei provides electricity at nuclear power plants and the uncontrolled chain-reaction fission of uranium and plutonium nuclei gives atomic bombs their destructive power.

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Transfer of EnergyEnergy is constantly moving from place to place and changing forms to make things happen.

Transformation of EnergySome of the energy transfers students explore will demonstrate energy changing from one form to another—energy transformations—while others will simply show energy moving from one object to another without changing form. Children are not asked to distinguish between these different types of transfers, so the term “transformation” is not presented as a unit student vocabulary word.

Transfers of energy involving change of form are referred to as energy transformations. (In this unit, they are simply called energy transfers.) Energy transformations are a constant in the world around us. Discussing some of the following examples will help children see that energy transfers and transformations are fundamental to almost everything that happens.

Energy Transformation

Example(s)

Light to Heat Children know that a blazing sun makes their popsicles melt, the asphalt “burn,” and the inside of their cars stifling. They intuitively understand that the light energy in the sun’s rays is transformed to heat energy at Earth’s surface.

Heat to Light The glow that results when the metal coils of stovetops, ovens, toasters, and incandescent light bulbs are heated is a familiar example of the transformation of heat energy to light energy.

Heat to Motion The warmth provided by the sun is the driving force behind Earth’s winds—demonstrating a familiar example of the transformation of heat energy to the motion energy of air. Likewise, heat energy from deep within the Earth’s core is the driving force between such violent events as earthquakes and volcanic eruptions.

When heat energy moves from a burner to a pan to the water in the pan, the water eventually boils. The movement apparent in the boiling water again demonstrates the transformation of heat energy to motion energy.

Energy Transformation

Example(s)

Motion to Heat The moving parts of your car’s engine heat up as they slide past each other. This phenomenon results from friction, the force that resists movement. It demonstrates how motion energy can be transformed to heat energy.

Chemical to Light Glowsticks, fireworks, and matches demonstrate the transformation of chemical energy to light energy.

Light to Chemical The energy in sunlight is transformed into chemical energy by plants through the process of photosynthesis. Special pigments in plant leaves absorb the sun’s energy and use it to create the sugars the plants need to grow and function. (Plants, in turn, provide food [chemical] energy for humans and other organisms.)

Light energy also makes photography possible. Light, entering the camera as a picture is “shot,” strikes the film causing the silver salts coating the film to turn black (a chemical change) and produce a negative image.

Light to Electrical Solar panels are devices that harness light’s energy to produce electricity. Solar panels function like batteries, providing the electrons necessary to create an electric current. Solar panels are essentially collections of solar cells (referred to as photovoltaics, meaning “light-electricity”) that function by giving up electrons when struck by light. The “free” electrons provide the electrical current that powers an ever-expanding array of solar devices including calculators, parking meters, refrigerators, home heating and cooling systems, and satellites in space.

Electrical to Light Fluorescent lamps and LED lights are familiar examples of the transformation of electrical energy into light energy.

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Transfer of EnergyEnergy is constantly moving from place to place and changing forms to make things happen.

Transformation of EnergySome of the energy transfers students explore will demonstrate energy changing from one form to another—energy transformations—while others will simply show energy moving from one object to another without changing form. Children are not asked to distinguish between these different types of transfers, so the term “transformation” is not presented as a unit student vocabulary word.

Transfers of energy involving change of form are referred to as energy transformations. (In this unit, they are simply called energy transfers.) Energy transformations are a constant in the world around us. Discussing some of the following examples will help children see that energy transfers and transformations are fundamental to almost everything that happens.

Energy Transformation

Example(s)

Light to Heat Children know that a blazing sun makes their popsicles melt, the asphalt “burn,” and the inside of their cars stifling. They intuitively understand that the light energy in the sun’s rays is transformed to heat energy at Earth’s surface.

Heat to Light The glow that results when the metal coils of stovetops, ovens, toasters, and incandescent light bulbs are heated is a familiar example of the transformation of heat energy to light energy.

Heat to Motion The warmth provided by the sun is the driving force behind Earth’s winds—demonstrating a familiar example of the transformation of heat energy to the motion energy of air. Likewise, heat energy from deep within the Earth’s core is the driving force between such violent events as earthquakes and volcanic eruptions.

When heat energy moves from a burner to a pan to the water in the pan, the water eventually boils. The movement apparent in the boiling water again demonstrates the transformation of heat energy to motion energy.

Energy Transformation

Example(s)

Motion to Heat The moving parts of your car’s engine heat up as they slide past each other. This phenomenon results from friction, the force that resists movement. It demonstrates how motion energy can be transformed to heat energy.

Chemical to Light Glowsticks, fireworks, and matches demonstrate the transformation of chemical energy to light energy.

Light to Chemical The energy in sunlight is transformed into chemical energy by plants through the process of photosynthesis. Special pigments in plant leaves absorb the sun’s energy and use it to create the sugars the plants need to grow and function. (Plants, in turn, provide food [chemical] energy for humans and other organisms.)

Light energy also makes photography possible. Light, entering the camera as a picture is “shot,” strikes the film causing the silver salts coating the film to turn black (a chemical change) and produce a negative image.

Light to Electrical Solar panels are devices that harness light’s energy to produce electricity. Solar panels function like batteries, providing the electrons necessary to create an electric current. Solar panels are essentially collections of solar cells (referred to as photovoltaics, meaning “light-electricity”) that function by giving up electrons when struck by light. The “free” electrons provide the electrical current that powers an ever-expanding array of solar devices including calculators, parking meters, refrigerators, home heating and cooling systems, and satellites in space.

Electrical to Light Fluorescent lamps and LED lights are familiar examples of the transformation of electrical energy into light energy.

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Energy Transformation

Example(s)

Sound to Electrical/ Electrical to Sound

A microphone converts sound energy to electrical energy. When you speak into a microphone the energy possessed by the sound waves “carrying” your voice causes a membrane within the microphone to move. The moving membrane causes an attached magnet to move within a coil, resulting in the generation of an electric current. The reverse process occurs to translate this electric current to the amplified sound of your voice emanating from a loudspeaker.

Sound waves of high frequencies, known as ultrasound, allow us to peer inside the human body or find hairline cracks in the metal of an airplane’s wing. Ultrasound machines direct high-frequency sound waves towards a tissue, organ, or object under analysis. The sound waves, bouncing back from the structure like an echo, are converted into electrical energy by a computer and then translated into a detailed image for study.

Motion to Gravitational/ Gravitational to Motion

A baseball hit high into left field, a football kicked over a field goal, and a child pushed to the high point of a swing all show the gravitational energy that can be gained through motion.

A sled descending a hill, a kayak riding the rapids, and a tree falling in the forest are examples of gravitational energy being converted to motion.

Swings and pendulums demonstrate the cyclic transformation of energy from motion energy to gravitational energy and from gravitational energy back to motion energy, over and over again.

Energy Transformation

Example(s)

Motion to Elastic/Elastic to Motion (plus Gravitational)

Children have abundant firsthand experience with the transformation of motion energy to elastic energy and elastic energy back to motion energy. Rubber bands and rubber band gliders, slingshots, catapults, and pop-up toys are some of the ways that children discover how stretching or compressing elastic objects stores elastic energy that produces motion when released.

(With bouncing toys and equipment such as trampolines and pogo sticks, gravitational energy also plays a role. A cycle of energy transformations repeats with each bounce: elastic energy is transformed to motion energy [the bounce]; motion energy is transformed to gravitational [potential] energy [the child rising]; gravitational energy is transformed to motion energy [the child falling]; motion energy is transformed to elastic energy [the child landing and compressing the pogo stick spring or stretching the trampoline]. This process repeats itself again and again.)

Electrical to Heat Toasters, electric ranges, and ovens demonstrate how the energy in electricity can be converted to the heat energy that cooks our food.

Electrical to Motion The moving parts of household appliances, such as the blades of a fan, the beaters of a mixer, or the agitator in a washing machine, demonstrate how the energy in electricity can be converted into the energy of motion.

Motion to Sound Plucking a guitar string, tapping a drum, vibrating our vocal chords, and playing the piano are some of the ways that motion is transformed into sound.

Chemical to Electrical The batteries in our cars, cell phones, flashlights, and portable MP3 players demonstrate how chemical energy can be converted to electrical energy. Within batteries, a chemical reaction supplies free electrons. The electrons collect on the negative end or terminal of the battery. If a connection is made between the negative and positive terminals—in many devices, this occurs when a switch is flipped—the electrons will flow from the negative to the positive terminal, creating the electrical current that makes cell phones and other battery-operated devices run.

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Energy Transformation

Example(s)

Sound to Electrical/ Electrical to Sound

A microphone converts sound energy to electrical energy. When you speak into a microphone the energy possessed by the sound waves “carrying” your voice causes a membrane within the microphone to move. The moving membrane causes an attached magnet to move within a coil, resulting in the generation of an electric current. The reverse process occurs to translate this electric current to the amplified sound of your voice emanating from a loudspeaker.

Sound waves of high frequencies, known as ultrasound, allow us to peer inside the human body or find hairline cracks in the metal of an airplane’s wing. Ultrasound machines direct high-frequency sound waves towards a tissue, organ, or object under analysis. The sound waves, bouncing back from the structure like an echo, are converted into electrical energy by a computer and then translated into a detailed image for study.

Motion to Gravitational/ Gravitational to Motion

A baseball hit high into left field, a football kicked over a field goal, and a child pushed to the high point of a swing all show the gravitational energy that can be gained through motion.

A sled descending a hill, a kayak riding the rapids, and a tree falling in the forest are examples of gravitational energy being converted to motion.

Swings and pendulums demonstrate the cyclic transformation of energy from motion energy to gravitational energy and from gravitational energy back to motion energy, over and over again.

Energy Transformation

Example(s)

Motion to Elastic/Elastic to Motion (plus Gravitational)

Children have abundant firsthand experience with the transformation of motion energy to elastic energy and elastic energy back to motion energy. Rubber bands and rubber band gliders, slingshots, catapults, and pop-up toys are some of the ways that children discover how stretching or compressing elastic objects stores elastic energy that produces motion when released.

(With bouncing toys and equipment such as trampolines and pogo sticks, gravitational energy also plays a role. A cycle of energy transformations repeats with each bounce: elastic energy is transformed to motion energy [the bounce]; motion energy is transformed to gravitational [potential] energy [the child rising]; gravitational energy is transformed to motion energy [the child falling]; motion energy is transformed to elastic energy [the child landing and compressing the pogo stick spring or stretching the trampoline]. This process repeats itself again and again.)

Electrical to Heat Toasters, electric ranges, and ovens demonstrate how the energy in electricity can be converted to the heat energy that cooks our food.

Electrical to Motion The moving parts of household appliances, such as the blades of a fan, the beaters of a mixer, or the agitator in a washing machine, demonstrate how the energy in electricity can be converted into the energy of motion.

Motion to Sound Plucking a guitar string, tapping a drum, vibrating our vocal chords, and playing the piano are some of the ways that motion is transformed into sound.

Chemical to Electrical The batteries in our cars, cell phones, flashlights, and portable MP3 players demonstrate how chemical energy can be converted to electrical energy. Within batteries, a chemical reaction supplies free electrons. The electrons collect on the negative end or terminal of the battery. If a connection is made between the negative and positive terminals—in many devices, this occurs when a switch is flipped—the electrons will flow from the negative to the positive terminal, creating the electrical current that makes cell phones and other battery-operated devices run.

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Energy Transformation

Example(s)

Chemical to Motion The transformation of chemical energy to the energy of motion gets us from place to place. From the fuels that power our cars, buses, trucks, planes, and trains, to the “fuel” that powers our muscle cells, chemical energy is being harnessed to get us where we want to go. In most engines the chemical energy is first turned to heat; the heat energy is then transformed into motion energy.

Chemical to Heat (to Motion to Electrical)

The burning of wood or fuel (coal and oil, for example) demonstrates how energy stored in chemical bonds can be converted to heat.

(Many power plants use the heat energy produced when fuels such as coal, oil, and natural gas are burned to boil water and create steam. In turn, the steam is used to turn huge turbines. These turbines are used to generate electricity.)

Transforming Energy from One Form to Severalcommon misconceptionStudents often think that one form of energy can only be changed to one other form rather than to multiple forms.

Many transfers of energy involve the transformation of energy from one form to several forms. Some of the examples listed in the table above demonstrate this point. Burning a log converts the chemical energy possessed by its wood into light, heat, and even sound energy (the sound of a crackling fireplace). The electrical energy of a toaster is transformed not only into the heat energy that toasts your bread, but also into the light energy evident in its glowing coils. The gravitational energy possessed by a roller coaster at the top of a hill is converted into the motion energy of its descending cars, the heat energy (resulting from friction) of its tracks and wheels, and the sound energy of its rattling cars and rails.

In Lesson 3, students discover this phenomenon firsthand as they map the energy transfers that occur when they operate a variety of toys. A number of these toys will show energy being transformed from one form to several. (In fact, since some of the energy used to operate each toy is transformed to heat energy, all the toys actually demonstrate the transformation of energy from one form to several. Students, however, are unlikely to make this connection since the amount of heat energy generated is virtually imperceptible.)

Machines: Making Use of Energy TransfersMany of the examples of energy transformations cited in the table involve machines. Toasters, ovens, ranges, fans, washing machines, refrigerators, computers, calculators, and engines are just some of the many machines that we rely on to make our lives easier. Machines are designed to facilitate the energy transfers necessary to make something specific occur. In Lesson 4, students will design boat “machines” that transfer a variety of energy forms (chemical, elastic, and motion) to make their boats “go.” They will also read in their student reference books about the energy transfers that occur to make some real boats “go.”

Sailboats work by capturing the wind in their sails. As the wind is caught, its motion energy is transferred to the motion energy of the boat, moving it across the water.

Rowboats, canoes, and kayaks rely on muscle power (and the water’s current) to propel them forward. The chemical energy in a paddler’s or rower’s muscles are used to move their arms. The motion energy of their arms is transferred to the oars and paddles, and eventually to the boat itself, moving it where they want it to go.

Power boats operate by burning fuel (gasoline or diesel). As the fuel is burned in the motor, the heat energy produced is usually transferred to the motion energy of a spinning propeller. As the propeller spins, it pushes the water backwards, moving the boat forward.

Machines and the Spirit of InventionAnother theme running through this unit is the spirit of invention. Over the course of this unit, students contemplate the design of various machines, become familiar with several well-known inventors, build machines that utilize energy transfers themselves, and even design their own inventions.

Heat TransferEnergy does not always change form as it moves from object to object or place to place. This is particularly evident with heat energy. To bring about the chemical changes we associate with “cooked” food, heat flows from the burner on your stove to the pan resting upon it, and then to the food it contains. Heat flows from campfires to campers’ marshmallows. It flows from the sand warmed by the sun to the air above it, creating onshore sea breezes.

| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN

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Energy Transformation

Example(s)

Chemical to Motion The transformation of chemical energy to the energy of motion gets us from place to place. From the fuels that power our cars, buses, trucks, planes, and trains, to the “fuel” that powers our muscle cells, chemical energy is being harnessed to get us where we want to go. In most engines the chemical energy is first turned to heat; the heat energy is then transformed into motion energy.

Chemical to Heat (to Motion to Electrical)

The burning of wood or fuel (coal and oil, for example) demonstrates how energy stored in chemical bonds can be converted to heat.

(Many power plants use the heat energy produced when fuels such as coal, oil, and natural gas are burned to boil water and create steam. In turn, the steam is used to turn huge turbines. These turbines are used to generate electricity.)

Transforming Energy from One Form to Severalcommon misconceptionStudents often think that one form of energy can only be changed to one other form rather than to multiple forms.

Many transfers of energy involve the transformation of energy from one form to several forms. Some of the examples listed in the table above demonstrate this point. Burning a log converts the chemical energy possessed by its wood into light, heat, and even sound energy (the sound of a crackling fireplace). The electrical energy of a toaster is transformed not only into the heat energy that toasts your bread, but also into the light energy evident in its glowing coils. The gravitational energy possessed by a roller coaster at the top of a hill is converted into the motion energy of its descending cars, the heat energy (resulting from friction) of its tracks and wheels, and the sound energy of its rattling cars and rails.

In Lesson 3, students discover this phenomenon firsthand as they map the energy transfers that occur when they operate a variety of toys. A number of these toys will show energy being transformed from one form to several. (In fact, since some of the energy used to operate each toy is transformed to heat energy, all the toys actually demonstrate the transformation of energy from one form to several. Students, however, are unlikely to make this connection since the amount of heat energy generated is virtually imperceptible.)

Machines: Making Use of Energy TransfersMany of the examples of energy transformations cited in the table involve machines. Toasters, ovens, ranges, fans, washing machines, refrigerators, computers, calculators, and engines are just some of the many machines that we rely on to make our lives easier. Machines are designed to facilitate the energy transfers necessary to make something specific occur. In Lesson 4, students will design boat “machines” that transfer a variety of energy forms (chemical, elastic, and motion) to make their boats “go.” They will also read in their student reference books about the energy transfers that occur to make some real boats “go.”

Sailboats work by capturing the wind in their sails. As the wind is caught, its motion energy is transferred to the motion energy of the boat, moving it across the water.

Rowboats, canoes, and kayaks rely on muscle power (and the water’s current) to propel them forward. The chemical energy in a paddler’s or rower’s muscles are used to move their arms. The motion energy of their arms is transferred to the oars and paddles, and eventually to the boat itself, moving it where they want it to go.

Power boats operate by burning fuel (gasoline or diesel). As the fuel is burned in the motor, the heat energy produced is usually transferred to the motion energy of a spinning propeller. As the propeller spins, it pushes the water backwards, moving the boat forward.

Machines and the Spirit of InventionAnother theme running through this unit is the spirit of invention. Over the course of this unit, students contemplate the design of various machines, become familiar with several well-known inventors, build machines that utilize energy transfers themselves, and even design their own inventions.

Heat TransferEnergy does not always change form as it moves from object to object or place to place. This is particularly evident with heat energy. To bring about the chemical changes we associate with “cooked” food, heat flows from the burner on your stove to the pan resting upon it, and then to the food it contains. Heat flows from campfires to campers’ marshmallows. It flows from the sand warmed by the sun to the air above it, creating onshore sea breezes.

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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How Does Heat Flow?

common misconceptionStudents often think that cool objects such as ice transfer their “coolness” to warmer objects, instead of realizing what actually happens—that warmer objects transfer some of their heat energy to cooler ones.

Heat energy spontaneously flows from hot items to cold ones. If two objects are at different temperatures, heat will naturally flow from the warmer object to the cooler one until both objects are at the same temperature.

The transfer of heat from a warmer object to a cooler one occurs in one (or more) of three different ways: conduction, convection, and radiation.

• Conduction is the most common way heat is transferred through solid materials. When a metal spoon is placed in a bowl of hot soup, it is through conduction that the exposed handle heats up. On a microscopic level, heat energy is being transferred by direct contact, from one molecule to the next, through the spoon all the way up to the handle. The molecules in the spoon closest to a heat source—those in the portion of the spoon submerged in the hot soup—vibrate faster and collide more frequently with nearby molecules, causing heat energy to be transferred up the spoon to the top of the handle with each collision. Substances that allow heat to travel through them are called conductors. Good conductors tend to be dense and include metals such as copper, silver, gold, and aluminum. Poor conductors, known as insulators, include plastic, rubber, air, and wood.

common misconceptionSome children may think that heat rises. It is hot air that rises, not heat. While students are not expected to understand that it is the energized particles (molecules) of “heated” air or a liquid that are rising and not “heat” itself, try to avoid using terms and phrases that might reinforce this misconception.

• Convection is the transfer of heat that occurs when the heated material itself moves from one place to another. Heat is transferred through fluids—liquids and gases (in a positive gravitational field such as Earth’s) through convection. The molecules in fluids (remember, this means gases too!) are free to move about. This means that energized molecules can move from one location to another, “carrying” their heat energy with them. When the molecules of a fluid gain heat energy, they move faster and “spread out.” As these heated molecules spread out they become less dense than nearby “unheated” molecules. Cooler, denser regions of the fluid settle beneath the warmer, less dense regions, pushing the warm regions up and out of the way. The temperature difference between a home’s attic and basement demonstrates this phenomenon—warm air rises and collects in the attic, while cooler, denser air settles in the basement.

In the presence of a constant heat source, such as the burner of a stove or the sun’s light, heat is transferred and ultimately circulated through convection currents. Fluids warmed by the heat source become less dense and rise; they are replaced by cooler, denser fluids which, in turn, are warmed and then replaced. This cycle continues, generating the convection currents that redistribute heat from its source. The impact

| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN

of convection currents on Earth is far-reaching, with wind, ocean currents, and the movement of Earth’s tectonic plates ultimately resulting from this kind of cycle.

• Radiation is the transfer of heat from a distance through electromagnetic waves (infrared, visible, or ultraviolet radiation). All objects (above 0 degrees Kelvin) possess some heat energy and thus emit electromagnetic radiation. Very hot objects like the sun emit higher energy waves—visible and ultraviolet light. Cooler objects emit lower energy infrared radiation. Electromagnetic waves travel without molecular “couriers” (in a vacuum—in the absence of matter) at the speed of light through space. When we bask in the warmth of the sun from a distance of 150 million kilometers (93,205,700 miles), we experience this phenomenon.

The properties of an object—such as its color, texture, and reflectivity—determine whether the radiation striking it will be absorbed or reflected. Radiated heat, commonly referred to as radiant heat, is transferred most readily to and from objects that are dull, dark in color, and rough in texture. Conversely, objects that are shiny, smooth, and light-colored are more likely to reflect radiant heat.

Heat Transfer and EfficiencyThe transfer of heat, flowing from hotter objects or areas to colder ones, cooks our food, warms and cools our homes, and dries our clothes. The fact that heat is always on the move also means that the heat energy tends to dissipate, meaning it spreads out, becoming unavailable for useful purposes. When you tell children to close the door on a cold winter’s day to keep the heat in, or to do the same on a hot summer’s day to keep the heat out, you are acknowledging this fact.

All devices produce heat. Some do it by design, such as toasters and ovens. Others, such as light bulbs and gas-powered engines, do so unavoidably; the heat produced serves no useful function. The heat released by these devices eventually dissipates and is not recaptured for further use. Dissipated heat represents inefficiency. Since no machine is 100% efficient (not even close!), ultimately some of the energy cycled through a machine will dissipate as heat energy. Devices that minimize heat loss are considered more energy-efficient than those that don’t. Because they waste less heat, energy-efficient devices use less energy overall to perform the same job.

Friction is the force that resists movement. Since all machines have moving parts, all machines are subject to friction. Friction results in the transfer of some of a machine’s motion energy to heat energy. This heat usually serves no purpose and is considered “wasted” energy.

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How Does Heat Flow?

common misconceptionStudents often think that cool objects such as ice transfer their “coolness” to warmer objects, instead of realizing what actually happens—that warmer objects transfer some of their heat energy to cooler ones.

Heat energy spontaneously flows from hot items to cold ones. If two objects are at different temperatures, heat will naturally flow from the warmer object to the cooler one until both objects are at the same temperature.

The transfer of heat from a warmer object to a cooler one occurs in one (or more) of three different ways: conduction, convection, and radiation.

• Conduction is the most common way heat is transferred through solid materials. When a metal spoon is placed in a bowl of hot soup, it is through conduction that the exposed handle heats up. On a microscopic level, heat energy is being transferred by direct contact, from one molecule to the next, through the spoon all the way up to the handle. The molecules in the spoon closest to a heat source—those in the portion of the spoon submerged in the hot soup—vibrate faster and collide more frequently with nearby molecules, causing heat energy to be transferred up the spoon to the top of the handle with each collision. Substances that allow heat to travel through them are called conductors. Good conductors tend to be dense and include metals such as copper, silver, gold, and aluminum. Poor conductors, known as insulators, include plastic, rubber, air, and wood.

common misconceptionSome children may think that heat rises. It is hot air that rises, not heat. While students are not expected to understand that it is the energized particles (molecules) of “heated” air or a liquid that are rising and not “heat” itself, try to avoid using terms and phrases that might reinforce this misconception.

• Convection is the transfer of heat that occurs when the heated material itself moves from one place to another. Heat is transferred through fluids—liquids and gases (in a positive gravitational field such as Earth’s) through convection. The molecules in fluids (remember, this means gases too!) are free to move about. This means that energized molecules can move from one location to another, “carrying” their heat energy with them. When the molecules of a fluid gain heat energy, they move faster and “spread out.” As these heated molecules spread out they become less dense than nearby “unheated” molecules. Cooler, denser regions of the fluid settle beneath the warmer, less dense regions, pushing the warm regions up and out of the way. The temperature difference between a home’s attic and basement demonstrates this phenomenon—warm air rises and collects in the attic, while cooler, denser air settles in the basement.

In the presence of a constant heat source, such as the burner of a stove or the sun’s light, heat is transferred and ultimately circulated through convection currents. Fluids warmed by the heat source become less dense and rise; they are replaced by cooler, denser fluids which, in turn, are warmed and then replaced. This cycle continues, generating the convection currents that redistribute heat from its source. The impact

of convection currents on Earth is far-reaching, with wind, ocean currents, and the movement of Earth’s tectonic plates ultimately resulting from this kind of cycle.

• Radiation is the transfer of heat from a distance through electromagnetic waves (infrared, visible, or ultraviolet radiation). All objects (above 0 degrees Kelvin) possess some heat energy and thus emit electromagnetic radiation. Very hot objects like the sun emit higher energy waves—visible and ultraviolet light. Cooler objects emit lower energy infrared radiation. Electromagnetic waves travel without molecular “couriers” (in a vacuum—in the absence of matter) at the speed of light through space. When we bask in the warmth of the sun from a distance of 150 million kilometers (93,205,700 miles), we experience this phenomenon.

The properties of an object—such as its color, texture, and reflectivity—determine whether the radiation striking it will be absorbed or reflected. Radiated heat, commonly referred to as radiant heat, is transferred most readily to and from objects that are dull, dark in color, and rough in texture. Conversely, objects that are shiny, smooth, and light-colored are more likely to reflect radiant heat.

Heat Transfer and EfficiencyThe transfer of heat, flowing from hotter objects or areas to colder ones, cooks our food, warms and cools our homes, and dries our clothes. The fact that heat is always on the move also means that the heat energy tends to dissipate, meaning it spreads out, becoming unavailable for useful purposes. When you tell children to close the door on a cold winter’s day to keep the heat in, or to do the same on a hot summer’s day to keep the heat out, you are acknowledging this fact.

All devices produce heat. Some do it by design, such as toasters and ovens. Others, such as light bulbs and gas-powered engines, do so unavoidably; the heat produced serves no useful function. The heat released by these devices eventually dissipates and is not recaptured for further use. Dissipated heat represents inefficiency. Since no machine is 100% efficient (not even close!), ultimately some of the energy cycled through a machine will dissipate as heat energy. Devices that minimize heat loss are considered more energy-efficient than those that don’t. Because they waste less heat, energy-efficient devices use less energy overall to perform the same job.

Friction is the force that resists movement. Since all machines have moving parts, all machines are subject to friction. Friction results in the transfer of some of a machine’s motion energy to heat energy. This heat usually serves no purpose and is considered “wasted” energy.

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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In Lesson 8, students will investigate energy efficiency as they compare compact fluorescent bulbs and incandescent bulbs. They will discover that incandescent bulbs release more heat energy than comparable compact fluorescent bulbs using the same amount of electrical energy.

Incandescent bulbs contain a filament that glows, producing light when heated. Electricity is used to heat the filament. Compact fluorescent bulbs contain a gas that becomes energized as electricity passes through it. The energized gas reacts with a coating on the inside of the bulb to produce light. 27w

100w

Compact fluorescent bulbs transform electrical energy into light more efficiently. If the same amount of energy input is supplied to both bulbs, a compact fluorescent bulb will produce more light output, or lumens, and less heat than an incandescent light bulb. In fact, about 90% of the electricity used by incandescent bulbs is “lost” as heat. Comparing the relative wattage—a measure of the electrical energy a light bulb uses per second—and lumens shows that compact fluorescent bulbs use about one-fourth the energy of incandescent bulbs while delivering the same amount of light. An 18-Watt compact fluorescent, for example, produces the same amount of light as a 75-Watt incandescent light bulb—meaning 57 fewer watts are used. Not only are compact fluorescent bulbs more efficient, they also last about ten times longer than incandescent bulbs. While compact fluorescent bulbs may cost more than incandescent light bulbs to purchase, their overall savings—in terms of operating expenses and energy conservation—should be weighed.

While CFLs are presented as the energy-efficient light bulb alternative in Lesson 8, they are not the only alternative. LEDs, for example, are also becoming widespread. LED stands for Light Emitting Diode. LEDs last a very long time (tens of thousands of hours). They are also extremely energy-efficient and durable. While LEDs are still too expensive for everyday use, they are often used in locations where it’s hard to change a light bulb, such as traffic signal lights, tail lights of automobiles, and business signs.

Limiting the Transfer of HeatMaximizing energy efficiency translates into lower operating expenses and a “cleaner” environment.

The current reliance on fossil fuels to “run” our homes, offices, cars, planes, and trains has an environmental cost—the burning of fossil fuels is a major source of air pollutants such as carbon dioxide, carbon monoxide, sulfur dioxide, and nitrogen oxides. Mining practices also have a detrimental environmental impact. Strip mining practices used to extract coal, for example, have led to filling in wetlands; and drainage of acid runoff from these mines harms nearby rivers and streams.

New technologies, such as compact fluorescent light bulbs, limit the dissipation of heat, saving consumers money, decreasing the demand for electricity, and resulting in less environmental damage.

While CFLs use less electricity, they are not totally environment “friendly.” They contain the heavy metal mercury which can pose an environmental threat if not disposed of properly. Students are presented with the pros and cons of many energy alternatives in their student reference books.

The relative heat conductivity of the materials used to make various items is also a key factor in limiting heat dissipation. Students discover this in Lesson 7 as they test a variety of materials to see which material or combination of materials is most effective at keeping heat energy from escaping a bottle of warm water.

Using Insulators to Limit Heat TransferAs indicated earlier, materials that are conductors (primarily metals) allow heat to flow through them easily, while materials that are insulators (rubber, wood, air, and plastic) limit the transfer of heat.

Trapping Air to Limit Heat TransferGases are good insulators because they are not dense and their molecules are relatively far apart. This is why humans will suffer from hypothermia after just a few minutes in 50oF water, but not in 50oF air. (Water is about 1,000 times as dense as air and is much more effective at conducting away body heat.)

Trapped air is a particularly effective insulator—trapped air cannot circulate and, consequently, cannot transfer heat by convection. Many insulating materials are designed to capitalize on this quality.

• Fiberglass insulation is made of glass spun into very fine, air-trapping fibers. (Think of the air pockets in spun cotton candy.) While glass is a relatively good conductor, fiberglass, which is made of long thin pieces of glass, does not conduct well. This characteristic, combined with fiberglass’ ability to trap air between its fibers, makes fiberglass an excellent insulator. Fiberglass blankets are sandwiched between the walls of most homes to keep them cool in the summer (keeping heat energy out) and warm in the winter (keeping heat energy in).

• Like fiberglass, foam makes use of trapped air to keep our hot drinks hot, and our cold drinks cold. Foam is formed

| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN

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In Lesson 8, students will investigate energy efficiency as they compare compact fluorescent bulbs and incandescent bulbs. They will discover that incandescent bulbs release more heat energy than comparable compact fluorescent bulbs using the same amount of electrical energy.

Incandescent bulbs contain a filament that glows, producing light when heated. Electricity is used to heat the filament. Compact fluorescent bulbs contain a gas that becomes energized as electricity passes through it. The energized gas reacts with a coating on the inside of the bulb to produce light. 27w

100w

Compact fluorescent bulbs transform electrical energy into light more efficiently. If the same amount of energy input is supplied to both bulbs, a compact fluorescent bulb will produce more light output, or lumens, and less heat than an incandescent light bulb. In fact, about 90% of the electricity used by incandescent bulbs is “lost” as heat. Comparing the relative wattage—a measure of the electrical energy a light bulb uses per second—and lumens shows that compact fluorescent bulbs use about one-fourth the energy of incandescent bulbs while delivering the same amount of light. An 18-Watt compact fluorescent, for example, produces the same amount of light as a 75-Watt incandescent light bulb—meaning 57 fewer watts are used. Not only are compact fluorescent bulbs more efficient, they also last about ten times longer than incandescent bulbs. While compact fluorescent bulbs may cost more than incandescent light bulbs to purchase, their overall savings—in terms of operating expenses and energy conservation—should be weighed.

While CFLs are presented as the energy-efficient light bulb alternative in Lesson 8, they are not the only alternative. LEDs, for example, are also becoming widespread. LED stands for Light Emitting Diode. LEDs last a very long time (tens of thousands of hours). They are also extremely energy-efficient and durable. While LEDs are still too expensive for everyday use, they are often used in locations where it’s hard to change a light bulb, such as traffic signal lights, tail lights of automobiles, and business signs.

Limiting the Transfer of HeatMaximizing energy efficiency translates into lower operating expenses and a “cleaner” environment.

The current reliance on fossil fuels to “run” our homes, offices, cars, planes, and trains has an environmental cost—the burning of fossil fuels is a major source of air pollutants such as carbon dioxide, carbon monoxide, sulfur dioxide, and nitrogen oxides. Mining practices also have a detrimental environmental impact. Strip mining practices used to extract coal, for example, have led to filling in wetlands; and drainage of acid runoff from these mines harms nearby rivers and streams.

New technologies, such as compact fluorescent light bulbs, limit the dissipation of heat, saving consumers money, decreasing the demand for electricity, and resulting in less environmental damage.

While CFLs use less electricity, they are not totally environment “friendly.” They contain the heavy metal mercury which can pose an environmental threat if not disposed of properly. Students are presented with the pros and cons of many energy alternatives in their student reference books.

The relative heat conductivity of the materials used to make various items is also a key factor in limiting heat dissipation. Students discover this in Lesson 7 as they test a variety of materials to see which material or combination of materials is most effective at keeping heat energy from escaping a bottle of warm water.

Using Insulators to Limit Heat TransferAs indicated earlier, materials that are conductors (primarily metals) allow heat to flow through them easily, while materials that are insulators (rubber, wood, air, and plastic) limit the transfer of heat.

Trapping Air to Limit Heat TransferGases are good insulators because they are not dense and their molecules are relatively far apart. This is why humans will suffer from hypothermia after just a few minutes in 50oF water, but not in 50oF air. (Water is about 1,000 times as dense as air and is much more effective at conducting away body heat.)

Trapped air is a particularly effective insulator—trapped air cannot circulate and, consequently, cannot transfer heat by convection. Many insulating materials are designed to capitalize on this quality.

• Fiberglass insulation is made of glass spun into very fine, air-trapping fibers. (Think of the air pockets in spun cotton candy.) While glass is a relatively good conductor, fiberglass, which is made of long thin pieces of glass, does not conduct well. This characteristic, combined with fiberglass’ ability to trap air between its fibers, makes fiberglass an excellent insulator. Fiberglass blankets are sandwiched between the walls of most homes to keep them cool in the summer (keeping heat energy out) and warm in the winter (keeping heat energy in).

• Like fiberglass, foam makes use of trapped air to keep our hot drinks hot, and our cold drinks cold. Foam is formed

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN 2�2

by blowing air into plastic (an insulator) to create a solid substance filled with air pockets.

• The high-tech insulators known as aerogels (also known as frozen smoke due to their appearance) are extremely porous silica structures made almost entirely of air (99.8 percent), making them phenomenal insulators.

• Wintry fabrics such as wool, fur, and synthetic fleece are valued for their ability to trap the air that keeps body heat from escaping. Layering clothing also effectively traps air (pockets of air get trapped between each layer of clothing) and limits the loss of body heat.

• Wood, a natural insulator with millions of tiny pores and air pockets, is a common insulating material used in windows, doors, and cooking utensils.

Using Reflective Materials to Limit Heat TransferReflectivity is another important characteristic that influences the degree of heat transfer. Reflective materials are incorporated into many products because they reflect rather than absorb radiated heat:

• People often wear white clothing to stay cool in the summer. Light colors reflect more radiant heat and visible light than dark colors, which absorb radiant heat and light.

• Fiberglass insulation frequently comes wrapped in a thin reflective foil of aluminum. The aluminum reflects heat back into the home during the winter months and back out of the home during the summer.

• Certain brands of extreme-weather clothing feature a thin plastic film lining that is highly reflective. The film reflects body heat back towards a person’s body rather than allowing it to escape into the surrounding air.

• Thermoses, particularly older models, also feature a reflective coating to limit the transfer of heat between the contents of the thermos and its surroundings.

Conservation of Energy

common misconceptionStudents often think that energy is a fuel-like quantity which is used up, and see machines as one of the ways that energy gets “used up.”

The awareness that energy changes from one form to another and that heat energy dissipates is the key to understanding one of the most basic principles of energy: energy can neither be created nor destroyed. This principle, known as the Conservation of Energy or First Law of Thermodynamics, dispels the notion of energy loss. Many items seem to run out of energy—a kicked ball eventually stops, spinning tops eventually fall over, and bikes screech to a halt when we slam on

the brakes. Encouraging students to trace the flow of energy will help them realize that energy was not lost, but transferred to other places and forms. This realization will provide the foundation for exploring the conservation of energy in later years.

Energy ConservationIf energy is never lost, why do we need to conserve energy? The need to conserve energy is a consequence of the forms of energy available at a given time rather than the total amount of energy present. The current “energy crisis” is due to the fact that energy is being transformed from easy-to-use forms, such as coal and petroleum, into harder-to-use forms, such as heat (which dissipates). At the current rate of consumption, most of the “easy-to-use” fossil fuels that we depend on will be depleted some time in this century. (While coal reserves are larger and not expected to run out for 200 years at the current rate of extraction, once the other fossil fuels are depleted, the rate of coal extraction is expected to increase significantly, thereby accelerating the depletion of coal as well.) Fossil fuels are not considered renewable. They take too long—millions of year!—to re-form. It will ultimately be necessary to shift our dependence from non-renewable forms of energy to renewable forms such as solar (light energy), wind (motion energy), hydropower (gravitational and motion energy), and geothermal (heat and motion energy).

The shift to renewable forms of energy is also seen as a means to protect the environment. The air pollutants produced by fossil-fuel burning power plants and automobiles (including carbon dioxide, methane, sulfuric, and nitrous oxides) contribute to acid rain, global warming, and smog.

Global warming is considered a consequence of the greenhouse effect. When sunlight (light energy) travels through the glass of a greenhouse (or the windows of a car), it is transferred to heat energy—warming up the air and surfaces inside. Unlike light energy, heat energy does not move through glass easily. The glass traps heat energy inside, keeping plants warm enough to live in the winter. Greenhouse gases, such as carbon dioxide, methane, and water vapor, form a layer in the atmosphere that acts in a similar way—allowing sunlight to pass through, but trapping heat energy inside. This is good to a degree—Earth’s average temperature would be much colder without these gases. But problems arise if this layer is allowed to get thicker and thicker, trapping more and more heat, and causing Earth’s temperature to gradually rise. Even a slight rise in Earth’s temperature can have huge consequences.

Acid rain forms when oxides of nitrogen and sulfite—produced primarily by burning fossil fuels—combine with moisture in the atmosphere to make nitric and sulfuric acids. The result is precipitation with a pH level less than 5.6 that adversely affects the regions receiving it. The associated environmental damage over time can be great, including the destruction

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by blowing air into plastic (an insulator) to create a solid substance filled with air pockets.

• The high-tech insulators known as aerogels (also known as frozen smoke due to their appearance) are extremely porous silica structures made almost entirely of air (99.8 percent), making them phenomenal insulators.

• Wintry fabrics such as wool, fur, and synthetic fleece are valued for their ability to trap the air that keeps body heat from escaping. Layering clothing also effectively traps air (pockets of air get trapped between each layer of clothing) and limits the loss of body heat.

• Wood, a natural insulator with millions of tiny pores and air pockets, is a common insulating material used in windows, doors, and cooking utensils.

Using Reflective Materials to Limit Heat TransferReflectivity is another important characteristic that influences the degree of heat transfer. Reflective materials are incorporated into many products because they reflect rather than absorb radiated heat:

• People often wear white clothing to stay cool in the summer. Light colors reflect more radiant heat and visible light than dark colors, which absorb radiant heat and light.

• Fiberglass insulation frequently comes wrapped in a thin reflective foil of aluminum. The aluminum reflects heat back into the home during the winter months and back out of the home during the summer.

• Certain brands of extreme-weather clothing feature a thin plastic film lining that is highly reflective. The film reflects body heat back towards a person’s body rather than allowing it to escape into the surrounding air.

• Thermoses, particularly older models, also feature a reflective coating to limit the transfer of heat between the contents of the thermos and its surroundings.

Conservation of Energy

common misconceptionStudents often think that energy is a fuel-like quantity which is used up, and see machines as one of the ways that energy gets “used up.”

The awareness that energy changes from one form to another and that heat energy dissipates is the key to understanding one of the most basic principles of energy: energy can neither be created nor destroyed. This principle, known as the Conservation of Energy or First Law of Thermodynamics, dispels the notion of energy loss. Many items seem to run out of energy—a kicked ball eventually stops, spinning tops eventually fall over, and bikes screech to a halt when we slam on

the brakes. Encouraging students to trace the flow of energy will help them realize that energy was not lost, but transferred to other places and forms. This realization will provide the foundation for exploring the conservation of energy in later years.

Energy ConservationIf energy is never lost, why do we need to conserve energy? The need to conserve energy is a consequence of the forms of energy available at a given time rather than the total amount of energy present. The current “energy crisis” is due to the fact that energy is being transformed from easy-to-use forms, such as coal and petroleum, into harder-to-use forms, such as heat (which dissipates). At the current rate of consumption, most of the “easy-to-use” fossil fuels that we depend on will be depleted some time in this century. (While coal reserves are larger and not expected to run out for 200 years at the current rate of extraction, once the other fossil fuels are depleted, the rate of coal extraction is expected to increase significantly, thereby accelerating the depletion of coal as well.) Fossil fuels are not considered renewable. They take too long—millions of year!—to re-form. It will ultimately be necessary to shift our dependence from non-renewable forms of energy to renewable forms such as solar (light energy), wind (motion energy), hydropower (gravitational and motion energy), and geothermal (heat and motion energy).

The shift to renewable forms of energy is also seen as a means to protect the environment. The air pollutants produced by fossil-fuel burning power plants and automobiles (including carbon dioxide, methane, sulfuric, and nitrous oxides) contribute to acid rain, global warming, and smog.

Global warming is considered a consequence of the greenhouse effect. When sunlight (light energy) travels through the glass of a greenhouse (or the windows of a car), it is transferred to heat energy—warming up the air and surfaces inside. Unlike light energy, heat energy does not move through glass easily. The glass traps heat energy inside, keeping plants warm enough to live in the winter. Greenhouse gases, such as carbon dioxide, methane, and water vapor, form a layer in the atmosphere that acts in a similar way—allowing sunlight to pass through, but trapping heat energy inside. This is good to a degree—Earth’s average temperature would be much colder without these gases. But problems arise if this layer is allowed to get thicker and thicker, trapping more and more heat, and causing Earth’s temperature to gradually rise. Even a slight rise in Earth’s temperature can have huge consequences.

Acid rain forms when oxides of nitrogen and sulfite—produced primarily by burning fossil fuels—combine with moisture in the atmosphere to make nitric and sulfuric acids. The result is precipitation with a pH level less than 5.6 that adversely affects the regions receiving it. The associated environmental damage over time can be great, including the destruction

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN 2�4

of lake, stream, and forest habitats. Acid rain also damages man-made materials and structures, dissolving marble, limestone, and sandstone and corroding metals, paints, textiles, and ceramics.

Smog—the dark, hazy atmosphere that covers many major cities (particularly in the summer time)—is a combination of the words smoke and fog. Smog consists of over 100 chemicals, but the two most harmful components are ground-level ozone and fine airborne particles. Coal-fired power plant and automobile emissions account for much of the smog produced. Smog is a serious health concern, especially to children and the elderly—causing respiratory infections and chronic lung diseases such as asthma.

The methods used to extract fossil fuels are also problematic—disrupting native habitats and contaminating local waters with harmful run-off.

Energy sources that can be used instead of fossil fuels to generate electricity are called alternative energy sources. While many are considered less harmful to the environment, each nonetheless has a cost, environmental and otherwise. In the student reference book, the children are presented with the following table outlining the pros and cons of various energy sources. Developing a sense of the tradeoffs involved in using these energy sources should help foster critical thinking as today’s students prepare to address the energy needs of the future.

Energy Sources—Pros and ConsSource of Energy

Pros Cons

Fossil Fuels Abundant (though a non-renewable source); somewhat inexpensive; used to produce many products; technologies are already in place that rely on them (e.g., gasoline- powered cars, coal- burning power plants)

Produce air pollution associated with smog, acid rain, and global warming; require storage and transportation; drilling, mining, and exploration is expensive, destructive to local habitats, and often dangerous; can raise the temperature of local waters when water used to cool power plants is released into them

Energy Sources—Pros and ConsSource of Energy

Pros Cons

Solar Energy Unlimited supply; no air or water pollution; no fuel is needed

Depends on sunlight; a backup energy source is needed; solar panels are expensive; requires lots of land; some toxic chemicals are used to manufacture solar cells and batteries

Wind Energy No air or water pollution; no fuel is needed; not very expensive to build; land around wind farms can be used for other purposes

Requires steady winds; lots of land is needed; some wind farms cause noise pollution; some consider them unsightly; bats and migrating birds are often killed by spinning turbines and wires

Geothermal Energy

No pollution; power stations do not take up much room—less impact on the environment; no fuel is needed; once you’ve built a geothermal power station, the energy is almost free

Only a few places are suitable to build a geothermal power station; geothermal sites sometimes stop producing steam; at some sites, hazardous gases and minerals come up from underground that require safe disposal

Hydropower Abundant; no pollution; no fuel is needed; easily stored in reservoirs; somewhat inexpensive

Requires a water supply; the necessary dams and reservoirs disrupt native habitats; the best sites are already developed

Nuclear Energy No air pollution; fuel (uranium) is abundant and somewhat inexpensive; reactors need to be refueled only about once a year; the energy obtained from one pound of uranium is equal to the amount of energy in approximately three million pounds of coal

Costly to build; many safety regulations are involved; risk of the escape of dangerous radioactive material raises public concern; requires long-term (at least 10,000 years), safe disposal of dangerous radioactive waste; raises the temperature of local waters when water used to cool the reactors is released into them

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2��

of lake, stream, and forest habitats. Acid rain also damages man-made materials and structures, dissolving marble, limestone, and sandstone and corroding metals, paints, textiles, and ceramics.

Smog—the dark, hazy atmosphere that covers many major cities (particularly in the summer time)—is a combination of the words smoke and fog. Smog consists of over 100 chemicals, but the two most harmful components are ground-level ozone and fine airborne particles. Coal-fired power plant and automobile emissions account for much of the smog produced. Smog is a serious health concern, especially to children and the elderly—causing respiratory infections and chronic lung diseases such as asthma.

The methods used to extract fossil fuels are also problematic—disrupting native habitats and contaminating local waters with harmful run-off.

Energy sources that can be used instead of fossil fuels to generate electricity are called alternative energy sources. While many are considered less harmful to the environment, each nonetheless has a cost, environmental and otherwise. In the student reference book, the children are presented with the following table outlining the pros and cons of various energy sources. Developing a sense of the tradeoffs involved in using these energy sources should help foster critical thinking as today’s students prepare to address the energy needs of the future.

Energy Sources—Pros and ConsSource of Energy

Pros Cons

Fossil Fuels Abundant (though a non-renewable source); somewhat inexpensive; used to produce many products; technologies are already in place that rely on them (e.g., gasoline- powered cars, coal- burning power plants)

Produce air pollution associated with smog, acid rain, and global warming; require storage and transportation; drilling, mining, and exploration is expensive, destructive to local habitats, and often dangerous; can raise the temperature of local waters when water used to cool power plants is released into them

Energy Sources—Pros and ConsSource of Energy

Pros Cons

Solar Energy Unlimited supply; no air or water pollution; no fuel is needed

Depends on sunlight; a backup energy source is needed; solar panels are expensive; requires lots of land; some toxic chemicals are used to manufacture solar cells and batteries

Wind Energy No air or water pollution; no fuel is needed; not very expensive to build; land around wind farms can be used for other purposes

Requires steady winds; lots of land is needed; some wind farms cause noise pollution; some consider them unsightly; bats and migrating birds are often killed by spinning turbines and wires

Geothermal Energy

No pollution; power stations do not take up much room—less impact on the environment; no fuel is needed; once you’ve built a geothermal power station, the energy is almost free

Only a few places are suitable to build a geothermal power station; geothermal sites sometimes stop producing steam; at some sites, hazardous gases and minerals come up from underground that require safe disposal

Hydropower Abundant; no pollution; no fuel is needed; easily stored in reservoirs; somewhat inexpensive

Requires a water supply; the necessary dams and reservoirs disrupt native habitats; the best sites are already developed

Nuclear Energy No air pollution; fuel (uranium) is abundant and somewhat inexpensive; reactors need to be refueled only about once a year; the energy obtained from one pound of uranium is equal to the amount of energy in approximately three million pounds of coal

Costly to build; many safety regulations are involved; risk of the escape of dangerous radioactive material raises public concern; requires long-term (at least 10,000 years), safe disposal of dangerous radioactive waste; raises the temperature of local waters when water used to cool the reactors is released into them

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

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2�6

Measuring EnergyAs stated in the beginning of this review, energy is a measurable property, not a substance. So how is energy measured? It turns out that energy is measured in many different ways using many different units. It helps to remember that each unit is simply a measure of energy and, as such, can be converted from one unit to another, just as energy itself is converted from one form to another.

Closely related to the measurement of energy is the measurement of temperature. Temperature is a measure of the average energy of motion of the atoms or molecules that make up a substance. It is important, however, to distinguish between average energy and total energy. Two objects could have the same temperature (meaning the average energy of their atoms and molecules is the same) but their total energy could be quite different. Total energy depends on the number of atoms and molecules present (the more atoms or molecules, the higher the total energy), as well as the type of atoms and molecules themselves. If, for example, you have two glasses of water in front of you, both registering the same temperature, and one has twice the volume as the other, the larger glass of water will have twice the total energy as the smaller one. This is why we are careful to say that “temperature is connected to the amount of heat energy in an object” but do not say that it is “a measure of the amount of heat energy in an object.”

There are three commonly used systems or scales for measuring temperature: Fahrenheit, Celsius, and Kelvin. Temperatures can be converted from one scale to another using the following equations:

• Fahrenheit to Celsius oC = (5/9) (oF - 32)

• Celsium to Fahrenheit oF = (9/5) oC + 32

• Celsius to Kelvin K = oC + 273

In the United States, a common unit of measure for comparing fuels is the British thermal unit (Btu). A Btu is the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit at sea level. One Btu is roughly equivalent to the amount of heat given off when one match head is burned. The following are the Btu equivalents of some familiar fuels:

• 1 gallon of gasoline = 124,000 Btu

• 1 gallon of diesel fuel = 139,000 Btu

• 1 gallon of home heating oil = 139,000 Btu

• 1 cubic foot of natural gas = 1,026 Btu

• 1 gallon of propane = 91,000 Btu

• 1 barrel (42 gallons) of crude oil = 5,800,000 Btu

Scientists around the world measure energy in joules. A joule (designated with a capital “J”) is the basic unit of energy in the metric system—representing the amount of energy it takes to lift 100 grams (.1 kg) of anything one meter. One thousand joules is the approximate equivalent of one Btu.

The energy potential of food is measured in Calories. A food Calorie (noted with a capital “C”) is actually a kilocalorie—equivalent to 1000 calories (small “c”). A calorie is the quantity of heat required to raise the temperature of one gram of water one degree Celsius at a pressure of one atmosphere (an arbitrary representative value for air pressure at sea level). One calorie is equivalent to 4.19 joules. Since one joule represents the amount of energy it takes to lift 100 grams of anything one meter, you can see that to “burn” one (little) calorie, you’d have to lift a 100 gram mass up and down a distance of one meter a little over four times. To burn one food Calorie, you’d have to do it about 4000 times!

Electrical power is measured in watts. Watts indicate the rate at which electricity is used. The amount of energy used by household appliances is usually described in kilowatt-hours. One kilowatt-hour (kWh), for which you are charged about $.10 - $.20, is equivalent to 1000 watts sustained for one hour. Energy-efficient refrigerators use about 1.4 kilowatt-hours per day, and about 500 kilowatt-hours per year. One kilowatt-hour of electricity is equivalent to 3,412 Btu.

“Energy” Impact StatementClearly “energy” is an immense topic. Every discipline of science (biology, geology, ecology, physics, medicine, chemistry, meteorology, astronomy, and so on) seeks to understand energy and its impact—on life, molecular behavior, the movement of Earth’s plates, weather patterns, chemical behavior, the lives of stars, and more.

At work (remember that scientists define energy in terms of its ability to perform work), doctors, engineers, scientists, gardeners, nutritionists, politicians, construction workers, and athletes rely on energy. At play, budding soccer stars, musicians, gazers of fireworks, and riders of swings have fun thanks to energy’s ability to make things happen.

Energy is inescapable! We hope that this unit opens students’ eyes to the energy all around them, helping them recognize the enormous role that energy plays in their lives and their world, and providing them with the foundation to further explore and understand the significance of energy as they progress through school, work, and life.

| ENERGY | TEaChER baCkGRouNd iNfoRmaTioN

Page 53: Solar Energy Field Trip

2��

Measuring EnergyAs stated in the beginning of this review, energy is a measurable property, not a substance. So how is energy measured? It turns out that energy is measured in many different ways using many different units. It helps to remember that each unit is simply a measure of energy and, as such, can be converted from one unit to another, just as energy itself is converted from one form to another.

Closely related to the measurement of energy is the measurement of temperature. Temperature is a measure of the average energy of motion of the atoms or molecules that make up a substance. It is important, however, to distinguish between average energy and total energy. Two objects could have the same temperature (meaning the average energy of their atoms and molecules is the same) but their total energy could be quite different. Total energy depends on the number of atoms and molecules present (the more atoms or molecules, the higher the total energy), as well as the type of atoms and molecules themselves. If, for example, you have two glasses of water in front of you, both registering the same temperature, and one has twice the volume as the other, the larger glass of water will have twice the total energy as the smaller one. This is why we are careful to say that “temperature is connected to the amount of heat energy in an object” but do not say that it is “a measure of the amount of heat energy in an object.”

There are three commonly used systems or scales for measuring temperature: Fahrenheit, Celsius, and Kelvin. Temperatures can be converted from one scale to another using the following equations:

• Fahrenheit to Celsius oC = (5/9) (oF - 32)

• Celsium to Fahrenheit oF = (9/5) oC + 32

• Celsius to Kelvin K = oC + 273

In the United States, a common unit of measure for comparing fuels is the British thermal unit (Btu). A Btu is the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit at sea level. One Btu is roughly equivalent to the amount of heat given off when one match head is burned. The following are the Btu equivalents of some familiar fuels:

• 1 gallon of gasoline = 124,000 Btu

• 1 gallon of diesel fuel = 139,000 Btu

• 1 gallon of home heating oil = 139,000 Btu

• 1 cubic foot of natural gas = 1,026 Btu

• 1 gallon of propane = 91,000 Btu

• 1 barrel (42 gallons) of crude oil = 5,800,000 Btu

Scientists around the world measure energy in joules. A joule (designated with a capital “J”) is the basic unit of energy in the metric system—representing the amount of energy it takes to lift 100 grams (.1 kg) of anything one meter. One thousand joules is the approximate equivalent of one Btu.

The energy potential of food is measured in Calories. A food Calorie (noted with a capital “C”) is actually a kilocalorie—equivalent to 1000 calories (small “c”). A calorie is the quantity of heat required to raise the temperature of one gram of water one degree Celsius at a pressure of one atmosphere (an arbitrary representative value for air pressure at sea level). One calorie is equivalent to 4.19 joules. Since one joule represents the amount of energy it takes to lift 100 grams of anything one meter, you can see that to “burn” one (little) calorie, you’d have to lift a 100 gram mass up and down a distance of one meter a little over four times. To burn one food Calorie, you’d have to do it about 4000 times!

Electrical power is measured in watts. Watts indicate the rate at which electricity is used. The amount of energy used by household appliances is usually described in kilowatt-hours. One kilowatt-hour (kWh), for which you are charged about $.10 - $.20, is equivalent to 1000 watts sustained for one hour. Energy-efficient refrigerators use about 1.4 kilowatt-hours per day, and about 500 kilowatt-hours per year. One kilowatt-hour of electricity is equivalent to 3,412 Btu.

“Energy” Impact StatementClearly “energy” is an immense topic. Every discipline of science (biology, geology, ecology, physics, medicine, chemistry, meteorology, astronomy, and so on) seeks to understand energy and its impact—on life, molecular behavior, the movement of Earth’s plates, weather patterns, chemical behavior, the lives of stars, and more.

At work (remember that scientists define energy in terms of its ability to perform work), doctors, engineers, scientists, gardeners, nutritionists, politicians, construction workers, and athletes rely on energy. At play, budding soccer stars, musicians, gazers of fireworks, and riders of swings have fun thanks to energy’s ability to make things happen.

Energy is inescapable! We hope that this unit opens students’ eyes to the energy all around them, helping them recognize the enormous role that energy plays in their lives and their world, and providing them with the foundation to further explore and understand the significance of energy as they progress through school, work, and life.

ENERGY | TEaChER baCkGRouNd iNfoRmaTioN |

Page 54: Solar Energy Field Trip

| ENERGY | sTaNdaRds 2��

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Page 55: Solar Energy Field Trip

2��ENERGY | sTaNdaRds |

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Page 56: Solar Energy Field Trip

| ENERGY | sTaNdaRds 260

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ity,

mec

hani

cal m

otio

n, s

ound

, nuc

lei,

and

the

natu

re o

f a c

hem

ical

. Ene

rgy

is tr

ansf

erre

d in

m

any

way

s.

FF

FF

OO

OO

FF

Hea

t mov

es in

pre

dict

able

way

s, flo

win

g fr

om

war

mer

obj

ects

to c

oole

r one

s, un

til b

oth

reac

h th

e sa

me

tem

pera

ture

.F

FF

O

Elec

tric

al c

ircui

ts p

rovi

de a

mea

ns o

f tr

ansf

errin

g el

ectr

ical

ene

rgy

whe

n he

at, l

ight

, so

und,

and

che

mic

al c

hang

es a

re p

rodu

ced.

EO

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

Stan

dard

s (P

age

3 of

8)

Page 57: Solar Energy Field Trip

261ENERGY | sTaNdaRds |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BIn

mos

t che

mic

al a

nd n

ucle

ar re

actio

ns, e

nerg

y is

tran

sfer

red

into

or o

ut o

f a s

yste

m. H

eat,

light

, mec

hani

cal m

otio

n, o

r ele

ctric

ity m

ight

al

l be

invo

lved

in s

uch

tran

sfer

s.

OO

The

sun

is a

maj

or s

ourc

e of

ene

rgy

for c

hang

es

on th

e ea

rth’

s su

rfac

e. T

he s

un lo

ses

ener

gy

by e

mitt

ing

light

. A ti

ny fr

actio

n of

that

ligh

t re

ache

s th

e ea

rth,

tran

sfer

ring

ener

gy fr

om th

e su

n to

the

eart

h. T

he s

un’s

ener

gy a

rriv

es a

s lig

ht w

ith a

rang

e of

wav

elen

gths

, con

sist

ing

of

visi

ble

light

, inf

rare

d, a

nd u

ltrav

iole

t rad

iatio

n.

O

C. L

ife S

cien

ce

Popu

latio

ns a

nd E

cosy

stem

s

For e

cosy

stem

s, th

e m

ajor

sou

rce

of e

nerg

y is

sun

light

. Ene

rgy

ente

ring

ecos

yste

ms

as

sunl

ight

is tr

ansf

erre

d by

pro

duce

rs in

to

chem

ical

ene

rgy

thro

ugh

phot

osyn

thes

is. T

hat

ener

gy th

en p

asse

s fr

om o

rgan

ism

to o

rgan

ism

in

food

web

s.

O

D. E

arth

and

Spa

ce S

cien

ce

Eart

h in

the

Sola

r Sys

tem

The

sun

is th

e m

ajor

sou

rce

of e

nerg

y fo

r ph

enom

ena

on th

e ea

rth’

s su

rfac

e, s

uch

as

grow

th o

f pla

nts,

win

ds, o

cean

cur

rent

s, an

d th

e w

ater

cyc

le. S

easo

ns re

sult

from

var

iatio

ns

in th

e am

ount

of t

he s

un’s

ener

gy h

ittin

g th

e su

rfac

e, d

ue to

the

tilt o

f the

ear

th’s

rota

tion

on

its a

xis

and

the

leng

th o

f the

day

.

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

Stan

dard

s (P

age

4 of

8)

Page 58: Solar Energy Field Trip

| ENERGY | sTaNdaRds 262

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BE.

Sci

ence

and

Tec

hnol

ogy

Abi

litie

s of

Tec

hnol

ogic

al D

esig

n

Des

ign

a so

lutio

n or

pro

duct

.F

Impl

emen

t a p

ropo

sed

desi

gn.

O

Und

erst

andi

ngs

abou

t Sci

ence

and

Tec

hnol

ogy

Peop

le h

ave

alw

ays

had

ques

tions

abo

ut

thei

r wor

ld. S

cien

ce is

one

way

of a

nsw

erin

g qu

estio

ns a

nd e

xpla

inin

g th

e na

tura

l wor

ld.

(Gra

des

K-4)

OO

Scie

ntis

ts a

nd e

ngin

eers

oft

en w

ork

in te

ams

with

diff

eren

t ind

ivid

uals

doi

ng d

iffer

ent

thin

gs th

at c

ontr

ibut

e to

the

resu

lts. T

his

unde

rsta

ndin

g fo

cuse

s pr

imar

ily o

n te

ams

wor

king

toge

ther

and

sec

onda

rily,

on

the

com

bina

tion

of s

cien

tist a

nd e

ngin

eer t

eam

s. (G

rade

s K-

4)

O

Man

y di

ffere

nt p

eopl

e in

diff

eren

t cul

ture

s ha

ve

mad

e an

d co

ntin

ue to

mak

e co

ntrib

utio

ns to

sc

ienc

e an

d te

chno

logy

. O

Scie

nce

and

tech

nolo

gy a

re re

cipr

ocal

. Sc

ienc

e he

lps

driv

e te

chno

logy

, as

it ad

dres

ses

ques

tions

that

dem

and

mor

e so

phis

ticat

ed

inst

rum

ents

and

pro

vide

s pr

inci

ples

for b

ette

r in

stru

men

tatio

n an

d te

chni

que.

Tec

hnol

ogy

is e

ssen

tial t

o sc

ienc

e, b

ecau

se it

pro

vide

s in

stru

men

ts a

nd te

chni

ques

that

ena

ble

obse

rvat

ions

of o

bjec

ts a

nd p

heno

men

a th

at

are

othe

rwis

e un

obse

rvab

le d

ue to

fact

ors

such

as

quan

tity,

dis

tanc

e, lo

catio

n, s

ize,

and

sp

eed.

Tec

hnol

ogy

also

pro

vide

s to

ols

for

inve

stig

atio

ns, i

nqui

ry, a

nd a

naly

sis.

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

Stan

dard

s (P

age

5 of

8)

Page 59: Solar Energy Field Trip

263ENERGY | sTaNdaRds |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BPe

rfec

tly d

esig

ned

solu

tions

do

not e

xist

. All

tech

nolo

gica

l sol

utio

ns h

ave

trad

e-of

fs, s

uch

as s

afet

y, c

ost,

effic

ienc

y, a

nd a

ppea

ranc

e.

Engi

neer

s of

ten

build

in b

ack-

up s

yste

ms

to

prov

ide

safe

ty. R

isk

is p

art o

f liv

ing

in a

hig

hly

tech

nolo

gica

l wor

ld. R

educ

ing

risk

ofte

n re

sults

in

new

tech

nolo

gy.

O

Tech

nolo

gica

l des

igns

hav

e co

nstr

aint

s. So

me

cons

trai

nts

are

unav

oida

ble,

for e

xam

ple,

pr

oper

ties

of m

ater

ials

, or e

ffect

s of

wea

ther

an

d fr

ictio

n; o

ther

con

stra

ints

lim

it ch

oice

s in

the

desi

gn, f

or e

xam

ple,

env

ironm

enta

l pr

otec

tion,

hum

an s

afet

y, a

nd a

esth

etic

s.

O

F. S

cien

ce in

Per

sona

l and

Soc

ial P

ersp

ecti

ves

Pers

onal

Hea

lth

Food

pro

vide

s en

ergy

and

nut

rient

s fo

r gro

wth

an

d de

velo

pmen

t. N

utrit

ion

requ

irem

ents

var

y w

ith b

ody

wei

ght,

age,

sex

, act

ivity

, and

bod

y fu

nctio

ning

.

OO

Nat

ural

env

ironm

ents

may

con

tain

sub

stan

ces

(for e

xam

ple,

rado

n an

d le

ad) t

hat a

re h

arm

ful

to h

uman

bei

ngs.

Mai

ntai

ning

env

ironm

enta

l he

alth

invo

lves

est

ablis

hing

or m

onito

ring

qual

ity s

tand

ards

rela

ted

to u

se o

f soi

l, w

ater

, an

d ai

r.

O

Scie

nce

and

Tech

nolo

gy in

Soc

iety

Scie

nce

influ

ence

s soc

iety

thro

ugh

its k

now

ledg

e an

d w

orld

vie

w. S

cien

tific

kno

wle

dge

and

the

proc

edur

es u

sed

by sc

ient

ists i

nflu

ence

the

way

man

y in

divi

dual

s in

soci

ety

thin

k ab

out

them

selv

es, o

ther

s, an

d th

e en

viro

nmen

t. Th

e ef

fect

of s

cien

ce o

n so

ciet

y is

neith

er e

ntire

ly

bene

ficia

l nor

ent

irely

det

rimen

tal.

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

Stan

dard

s (P

age

6 of

8)

Page 60: Solar Energy Field Trip

| ENERGY | sTaNdaRds 264

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BSc

ienc

e an

d te

chno

logy

hav

e ad

vanc

ed

thro

ugh

cont

ribut

ions

of m

any

diffe

rent

pe

ople

, in

diffe

rent

cul

ture

s, at

diff

eren

t tim

es in

his

tory

. Sci

ence

and

tech

nolo

gy h

ave

cont

ribut

ed e

norm

ousl

y to

eco

nom

ic g

row

th

and

prod

uctiv

ity a

mon

g so

ciet

ies

and

grou

ps

with

in s

ocie

ties.

F

G. H

isto

ry a

nd N

atur

e of

Sci

ence

Scie

nce

as a

Hum

an E

ndea

vor

Wom

en a

nd m

en o

f var

ious

soc

ial a

nd e

thni

c ba

ckgr

ound

s-an

d w

ith d

iver

se in

tere

sts,

tale

nts,

qual

ities

, and

mot

ivat

ions

-eng

age

in th

e ac

tiviti

es o

f sci

ence

, eng

inee

ring,

and

rela

ted

field

s su

ch a

s th

e he

alth

pro

fess

ions

. Som

e sc

ient

ists

wor

k in

team

s, an

d so

me

wor

k al

one,

bu

t all

com

mun

icat

e ex

tens

ivel

y w

ith o

ther

s.

O

Scie

nce

requ

ires

diffe

rent

abi

litie

s, de

pend

ing

on s

uch

fact

ors

as th

e fie

ld o

f stu

dy a

nd ty

pe

of in

quiry

. Sci

ence

is v

ery

muc

h a

hum

an

ende

avor

, and

the

wor

k of

sci

ence

relie

s on

ba

sic

hum

an q

ualit

ies,

such

as

reas

onin

g,

insi

ght,

ener

gy, s

kill,

and

cre

ativ

ity-a

s w

ell a

s on

sci

entif

ic h

abits

of m

ind,

suc

h as

inte

llect

ual

hone

sty,

tole

ranc

e of

am

bigu

ity, s

kept

icis

m,

and

open

ness

to n

ew id

eas.

OO

His

tory

of S

cien

ce

Man

y in

divi

dual

s ha

ve c

ontr

ibut

ed to

the

trad

ition

s of

sci

ence

. Stu

dyin

g so

me

of th

ese

indi

vidu

als

prov

ides

furt

her u

nder

stan

ding

of

scie

ntifi

c in

quiry

, sci

ence

as

a hu

man

end

eavo

r, th

e na

ture

of s

cien

ce, a

nd th

e re

latio

nshi

ps

betw

een

scie

nce

and

soci

ety.

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

Stan

dard

s (P

age

7 of

8)

Page 61: Solar Energy Field Trip

26�ENERGY | sTaNdaRds |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BSc

ienc

e an

d te

chno

logy

hav

e ad

vanc

ed

thro

ugh

cont

ribut

ions

of m

any

diffe

rent

pe

ople

, in

diffe

rent

cul

ture

s, at

diff

eren

t tim

es in

his

tory

. Sci

ence

and

tech

nolo

gy h

ave

cont

ribut

ed e

norm

ousl

y to

eco

nom

ic g

row

th

and

prod

uctiv

ity a

mon

g so

ciet

ies

and

grou

ps

with

in s

ocie

ties.

F

G. H

isto

ry a

nd N

atur

e of

Sci

ence

Scie

nce

as a

Hum

an E

ndea

vor

Wom

en a

nd m

en o

f var

ious

soc

ial a

nd e

thni

c ba

ckgr

ound

s-an

d w

ith d

iver

se in

tere

sts,

tale

nts,

qual

ities

, and

mot

ivat

ions

-eng

age

in th

e ac

tiviti

es o

f sci

ence

, eng

inee

ring,

and

rela

ted

field

s su

ch a

s th

e he

alth

pro

fess

ions

. Som

e sc

ient

ists

wor

k in

team

s, an

d so

me

wor

k al

one,

bu

t all

com

mun

icat

e ex

tens

ivel

y w

ith o

ther

s.

O

Scie

nce

requ

ires

diffe

rent

abi

litie

s, de

pend

ing

on s

uch

fact

ors

as th

e fie

ld o

f stu

dy a

nd ty

pe

of in

quiry

. Sci

ence

is v

ery

muc

h a

hum

an

ende

avor

, and

the

wor

k of

sci

ence

relie

s on

ba

sic

hum

an q

ualit

ies,

such

as

reas

onin

g,

insi

ght,

ener

gy, s

kill,

and

cre

ativ

ity-a

s w

ell a

s on

sci

entif

ic h

abits

of m

ind,

suc

h as

inte

llect

ual

hone

sty,

tole

ranc

e of

am

bigu

ity, s

kept

icis

m,

and

open

ness

to n

ew id

eas.

OO

His

tory

of S

cien

ce

Man

y in

divi

dual

s ha

ve c

ontr

ibut

ed to

the

trad

ition

s of

sci

ence

. Stu

dyin

g so

me

of th

ese

indi

vidu

als

prov

ides

furt

her u

nder

stan

ding

of

scie

ntifi

c in

quiry

, sci

ence

as

a hu

man

end

eavo

r, th

e na

ture

of s

cien

ce, a

nd th

e re

latio

nshi

ps

betw

een

scie

nce

and

soci

ety.

O

Nat

iona

l Res

earc

h Co

unci

l. N

atio

nal S

cien

ce E

duca

tion

Stan

dard

s. W

ashi

ngto

n, D

.C.:

Nat

iona

l Aca

dem

y Pr

ess,

1996

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

STA

ND

ARD

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BIn

his

toric

al p

ersp

ectiv

e, s

cien

ce h

as b

een

prac

ticed

by

diffe

rent

indi

vidu

als

in d

iffer

ent

cultu

res.

In lo

okin

g at

the

hist

ory

of m

any

peop

les,

one

finds

that

sci

entis

ts a

nd e

ngin

eers

of

hig

h ac

hiev

emen

t are

con

side

red

to b

e am

ong

the

mos

t val

ued

cont

ribut

ors

to th

eir

cultu

re.

O

Trac

ing

the

hist

ory

of s

cien

ce c

an s

how

how

di

fficu

lt it

was

for s

cien

tific

inno

vato

rs to

bre

ak

thro

ugh

the

acce

pted

idea

s of

thei

r tim

e to

re

ach

the

conc

lusi

ons

that

we

curr

ently

take

for

gran

ted.

O

Uni

fyin

g Co

ncep

ts a

nd P

roce

sses

Evid

ence

, mod

els,

and

expl

anat

ion

OO

OO

ON

atio

nal R

esea

rch

Coun

cil.

Nat

iona

l Sci

ence

Edu

catio

n St

anda

rds.

Was

hing

ton,

D.C

.: N

atio

nal A

cade

my

Pres

s, 19

96

Stan

dard

s (P

age

8 of

8)

Page 62: Solar Energy Field Trip

| ENERGY | bENChmaRks 266

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

B1.

The

Nat

ure

of S

cien

ce

A. T

he S

cien

tific

Wor

ld V

iew

Resu

lts o

f sim

ilar s

cien

tific

inve

stig

atio

ns

seld

om tu

rn o

ut e

xact

ly th

e sa

me.

So

met

imes

this

is b

ecau

se o

f une

xpec

ted

diffe

renc

es in

the

thin

gs b

eing

inve

stig

ated

, so

met

imes

bec

ause

of u

nrea

lized

diff

eren

ces

in th

e m

etho

ds u

sed

or in

the

circ

umst

ance

s in

whi

ch th

e in

vest

igat

ion

is c

arrie

d ou

t, an

d so

met

imes

just

bec

ause

of u

ncer

tain

ties

in o

bser

vatio

ns. I

t is

not a

lway

s ea

sy to

tell

whi

ch.

OO

O

B. S

cien

tific

Inqu

iry

Des

crib

ing

thin

gs a

s ac

cura

tely

as

poss

ible

is

impo

rtan

t in

scie

nce

beca

use

it en

able

s pe

ople

to c

ompa

re th

eir o

bser

vatio

ns w

ith

thos

e of

oth

ers.

(Gra

des

K-2)

OO

OO

F

Scie

ntifi

c in

vest

igat

ions

may

take

man

y di

ffere

nt fo

rms,

incl

udin

g ob

serv

ing

wha

t thi

ngs

are

like

or w

hat i

s ha

ppen

ing

som

ewhe

re, c

olle

ctin

g sp

ecim

ens

for a

naly

sis,

and

doin

g ex

perim

ents

. In

vest

igat

ions

can

focu

s on

phy

sica

l, bi

olog

ical

, and

soc

ial q

uest

ions

.

OO

OO

OO

OO

OO

OO

Resu

lts o

f sci

entif

ic in

vest

igat

ions

are

se

ldom

exa

ctly

the

sam

e, b

ut if

the

diffe

renc

es a

re la

rge,

it is

impo

rtan

t to

try

to fi

gure

out

why

. One

reas

on fo

r fol

low

ing

dire

ctio

ns c

aref

ully

and

for k

eepi

ng re

cord

s of

one

’s w

ork

is to

pro

vide

info

rmat

ion

on

wha

t mig

ht h

ave

caus

ed th

e di

ffere

nces

.

OO

OO

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

1 o

f 10)

Page 63: Solar Energy Field Trip

26�ENERGY | bENChmaRks |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BSc

ient

ists

’ exp

lana

tions

abo

ut w

hat

happ

ens

in th

e w

orld

com

e pa

rtly

from

w

hat t

hey

obse

rve,

par

tly fr

om w

hat

they

thin

k. S

omet

imes

sci

entis

ts h

ave

diffe

rent

exp

lana

tions

for t

he s

ame

set o

f ob

serv

atio

ns. T

hat u

sual

ly le

ads

to th

eir

mak

ing

mor

e ob

serv

atio

ns to

reso

lve

the

diffe

renc

es.

FO

OO

OO

If m

ore

than

one

var

iabl

e ch

ange

s at

the

sam

e tim

e in

an

expe

rimen

t, th

e ou

tcom

e of

the

expe

rimen

t may

not

be

clea

rly

attr

ibut

able

to a

ny o

ne o

f the

var

iabl

es.

(Gra

des

6-8)

OO

F

C. T

he S

cien

tific

Ent

erpr

ise

Scie

nce

is a

n ad

vent

ure

that

peo

ple

ever

ywhe

re c

an ta

ke p

art i

n, a

s th

ey h

ave

for

man

y ce

ntur

ies.

O

Clea

r com

mun

icat

ion

is a

n es

sent

ial p

art o

f do

ing

scie

nce.

It e

nabl

es s

cien

tists

to in

form

ot

hers

abo

ut th

eir w

ork,

exp

ose

thei

r ide

as

to c

ritic

ism

by

othe

r sci

entis

ts, a

nd s

tay

info

rmed

abo

ut s

cien

tific

dis

cove

ries

arou

nd

the

wor

ld.

OO

OO

OO

OO

OF

OO

O

Doi

ng s

cien

ce in

volv

es m

any

diffe

rent

kin

ds

of w

ork

and

enga

ges

men

and

wom

en o

f all

ages

and

bac

kgro

unds

.O

2. T

he N

atur

e of

Mat

hem

atic

s

A. P

atte

rns

and

Rela

tions

hips

Mat

hem

atic

al id

eas

can

be re

pres

ente

d co

ncre

tely

, gra

phic

ally

, and

sym

bolic

ally

.O

OO

O

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

2 o

f 10)

Page 64: Solar Energy Field Trip

| ENERGY | bENChmaRks 26�

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

B3.

The

Nat

ure

of T

echn

olog

y

A. T

echn

olog

y an

d Sc

ienc

e

Thro

ugho

ut a

ll of

his

tory

, peo

ple

ever

ywhe

re h

ave

inve

nted

and

use

d to

ols.

Mos

t too

ls o

f tod

ay a

re d

iffer

ent f

rom

thos

e of

the

past

but

man

y ar

e m

odifi

catio

ns o

f ve

ry a

ncie

nt to

ols.

O

Mea

surin

g in

stru

men

ts c

an b

e us

ed to

ga

ther

acc

urat

e in

form

atio

n fo

r mak

ing

scie

ntifi

c co

mpa

rison

s of

obj

ects

and

eve

nts

and

for d

esig

ning

and

con

stru

ctin

g th

ings

th

at w

ill w

ork

prop

erly

.

OO

FO

Tech

nolo

gy e

xten

ds th

e ab

ility

of p

eopl

e to

cha

nge

the

wor

ld: t

o cu

t, sh

ape,

or p

ut

toge

ther

mat

eria

ls; t

o m

ove

thin

gs fr

om

one

plac

e to

ano

ther

; and

to re

ach

fart

her

with

thei

r han

ds, v

oice

s, se

nses

, and

min

ds.

The

chan

ges

may

be

for s

urvi

val n

eeds

su

ch a

s fo

od, s

helte

r, an

d de

fens

e, fo

r co

mm

unic

atio

n an

d tr

ansp

orta

tion,

or t

o ga

in k

now

ledg

e an

d ex

pres

s id

eas.

O

B. D

esig

n an

d Sy

stem

s

Ther

e is

no

perf

ect d

esig

n. D

esig

ns th

at a

re

best

in o

ne re

spec

t (sa

fety

or e

ase

of u

se,

for e

xam

ple)

may

be

infe

rior i

n ot

her w

ays

(cos

t or a

ppea

ranc

e). U

sual

ly s

ome

feat

ures

m

ust b

e sa

crifi

ced

to g

et o

ther

s. H

ow s

uch

trad

e-of

fs a

re re

ceiv

ed d

epen

ds u

pon

whi

ch

feat

ures

are

em

phas

ized

and

whi

ch a

re

dow

npla

yed.

OO

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

3 o

f 10)

Page 65: Solar Energy Field Trip

26�ENERGY | bENChmaRks |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BEv

en a

goo

d de

sign

may

fail.

Som

etim

es

step

s ca

n be

take

n ah

ead

of ti

me

to re

duce

th

e lik

elih

ood

of fa

ilure

, but

it c

anno

t be

entir

ely

elim

inat

ed.

O

C. Is

sues

in T

echn

olog

y

Tech

nolo

gy h

as b

een

part

of l

ife o

n th

e ea

rth

sinc

e th

e ad

vent

of t

he h

uman

sp

ecie

s. L

ike

lang

uage

, ritu

al, c

omm

erce

, an

d th

e ar

ts, t

echn

olog

y is

an

intr

insi

c pa

rt o

f hum

an c

ultu

re, a

nd it

bot

h sh

apes

so

ciet

y an

d is

sha

ped

by it

. The

tech

nolo

gy

avai

labl

e to

peo

ple

grea

tly in

fluen

ces

wha

t th

eir l

ives

are

like

.

O

Any

inve

ntio

n is

like

ly to

lead

to o

ther

in

vent

ions

. Onc

e an

inve

ntio

n ex

ists

, peo

ple

are

likel

y to

thin

k up

way

s of

usi

ng it

that

w

ere

neve

r im

agin

ed a

t firs

t.

O

Tran

spor

tatio

n, c

omm

unic

atio

ns, n

utrit

ion,

sa

nita

tion,

hea

lth c

are,

ent

erta

inm

ent,

and

othe

r tec

hnol

ogie

s gi

ve la

rge

num

bers

of

peop

le to

day

the

good

s an

d se

rvic

es th

at

once

wer

e lu

xurie

s en

joye

d on

ly b

y th

e w

ealth

y. T

hese

ben

efits

are

not

equ

ally

av

aila

ble

to e

very

one.

O

Tech

nolo

gies

oft

en h

ave

draw

back

s as

wel

l as

ben

efits

. A te

chno

logy

that

hel

ps s

ome

peop

le o

r org

anis

ms

may

hur

t oth

ers-

eith

er d

elib

erat

ely

(as

wea

pons

can

) or

inad

vert

ently

(as

pest

icid

es c

an).

Whe

n ha

rm

occu

rs o

r see

ms

likel

y, c

hoic

es h

ave

to b

e m

ade

or n

ew s

olut

ions

foun

d.

O

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

4 o

f 10)

Page 66: Solar Energy Field Trip

| ENERGY | bENChmaRks 2�0

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

B4.

The

Phy

sica

l Set

ting

B. T

he E

arth

Thin

gs o

n or

nea

r the

ear

th a

re p

ulle

d to

war

d it

by th

e ea

rth’

s gr

avity

.O

O

Whe

n liq

uid

wat

er d

isap

pear

s, it

turn

s in

to

a ga

s (v

apor

) in

the

air a

nd c

an re

appe

ar a

s a

liqui

d w

hen

cool

ed, o

r as

a so

lid if

coo

led

belo

w th

e fr

eezi

ng p

oint

of w

ater

. Clo

uds

and

fog

are

mad

e of

tiny

dro

plet

s of

wat

er.

O

Air

is a

sub

stan

ce th

at s

urro

unds

us,

take

s up

spa

ce, a

nd w

hose

mov

emen

t we

feel

as

win

d.O

E. E

nerg

y Tr

ansf

orm

atio

n

Thin

gs th

at g

ive

off l

ight

oft

en a

lso

give

off

heat

. Hea

t is

prod

uced

by

mec

hani

cal a

nd

elec

tric

al m

achi

nes,

and

any

time

one

thin

g ru

bs a

gain

st s

omet

hing

els

e.

FO

Whe

n w

arm

er th

ings

are

put

with

coo

ler

ones

, the

war

m o

nes

lose

hea

t and

the

cool

on

es g

ain

it un

til th

ey a

re a

ll at

the

sam

e te

mpe

ratu

re. A

war

mer

obj

ect c

an w

arm

a

cool

er o

ne b

y co

ntac

t or a

t a d

ista

nce.

FF

FF

Som

e m

ater

ials

con

duct

hea

t muc

h be

tter

th

an o

ther

s. Po

or c

ondu

ctor

s ca

n re

duce

he

at lo

ss.

FF

F

Man

y ev

ents

invo

lve

tran

sfer

of e

nerg

y fr

om

one

obje

ct to

ano

ther

.F

FO

OO

OF

F

Mos

t pro

cess

es in

volv

e th

e tr

ansf

er o

f en

ergy

from

one

sys

tem

to a

noth

er.

Ener

gy c

an b

e tr

ansf

erre

d in

diff

eren

t way

s. (G

rade

s 6-

8)

FF

OO

OO

FF

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

5 o

f 10)

Page 67: Solar Energy Field Trip

2�1ENERGY | bENChmaRks |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BEn

ergy

app

ears

in d

iffer

ent f

orm

s. M

otio

n en

ergy

is a

ssoc

iate

d w

ith th

e sp

eed

of a

n ob

ject

. Hea

t ene

rgy

is a

ssoc

iate

d w

ith th

e te

mpe

ratu

re o

f an

obje

ct. G

ravi

tatio

nal

ener

gy is

ass

ocia

ted

with

the

heig

ht o

f an

obj

ect a

bove

a re

fere

nce

poin

t. El

astic

en

ergy

is a

ssoc

iate

d w

ith th

e st

retc

hing

of

an

elas

tic o

bjec

t. Ch

emic

al e

nerg

y is

as

soci

ated

with

the

chem

ical

com

posi

tion

of a

sub

stan

ce. W

ithin

a s

yste

m, e

nerg

y ca

n be

tran

sfor

med

from

one

form

to a

noth

er.

(Gra

des

6-8)

EF

FF

OO

OO

FF

G. T

he F

orce

s of

Nat

ure

The

eart

h’s

grav

ity p

ulls

any

obj

ect t

owar

d it

with

out t

ouch

ing

it.O

O

5. T

he L

ivin

g En

viro

nmen

t

E. F

low

of M

atte

r and

Ene

rgy

Alm

ost a

ll ki

nds

of a

nim

als’

food

can

be

trac

ed b

ack

to p

lant

s.O

Som

e so

urce

of “

ener

gy” i

s ne

eded

for a

ll or

gani

sms

to s

tay

aliv

e an

d gr

ow.

OO

6. T

he H

uman

Org

anis

m

C. B

asic

Fun

ctio

n

From

food

, peo

ple

obta

in e

nerg

y an

d m

ater

ials

for b

ody

repa

ir an

d gr

owth

. The

in

dige

stib

le p

arts

of f

ood

are

elim

inat

ed.

OO

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

6 o

f 10)

Page 68: Solar Energy Field Trip

| ENERGY | bENChmaRks 2�2

Ben

chm

arks

(Page

7 o

f 10)

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BE.

Phy

sica

l Hea

lth

Food

pro

vide

s en

ergy

and

mat

eria

ls fo

r gr

owth

and

repa

ir of

bod

y pa

rts.

Vita

min

s an

d m

iner

als,

pres

ent i

n sm

all a

mou

nts

in fo

od, a

re e

ssen

tial t

o ke

ep e

very

thin

g w

orki

ng w

ell.

As

peop

le g

row

up,

the

amou

nts

and

kind

s of

food

and

exe

rcis

e ne

eded

by

the

body

may

cha

nge.

OO

8. T

he D

esig

ned

Wor

ld

B. M

ater

ials

and

Man

ufac

turin

g

The

choi

ce o

f mat

eria

ls fo

r a jo

b de

pend

s on

th

eir p

rope

rtie

s an

d ho

w th

ey in

tera

ct w

ith

othe

r mat

eria

ls. (

Gra

des

6-8)

FO

C. E

nerg

y So

urce

s an

d U

ses

Mov

ing

air a

nd w

ater

can

be

used

to ru

n m

achi

nes.

FF

O

The

sun

is th

e m

ain

sour

ce o

f ene

rgy

for

peop

le a

nd th

ey u

se it

in v

ario

us w

ays.

The

ener

gy in

foss

il fu

els

such

as

oil a

nd c

oal

com

es fr

om th

e su

n in

dire

ctly

, bec

ause

the

fuel

s co

me

from

pla

nts

that

gre

w lo

ng a

go.

OO

Som

e en

ergy

sou

rces

cos

t les

s th

an o

ther

s an

d so

me

caus

e le

ss p

ollu

tion

than

oth

ers.

FO

Peop

le tr

y to

con

serv

e en

ergy

in o

rder

to

slo

w d

own

the

depl

etio

n of

ene

rgy

reso

urce

s an

d/or

to s

ave

mon

ey.

OF

Ener

gy c

an c

hang

e fr

om o

ne fo

rm to

an

othe

r, al

thou

gh in

the

proc

ess

som

e en

ergy

is a

lway

s co

nver

ted

to h

eat.

Som

e sy

stem

s tr

ansf

orm

ene

rgy

with

less

loss

of

heat

than

oth

ers.

(Gra

des

6-8)

FO

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Page 69: Solar Energy Field Trip

2�3ENERGY | bENChmaRks |

Ben

chm

arks

(Page

8 o

f 10)

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

B9.

The

Mat

hem

atic

al W

orld

A. N

umbe

rs

Whe

n pe

ople

car

e ab

out w

hat i

s be

ing

coun

ted

or m

easu

red,

it is

impo

rtan

t for

th

em to

say

wha

t the

uni

ts a

re (t

hree

de

gree

s Fa

hren

heit

is d

iffer

ent f

rom

thre

e ce

ntim

eter

s, th

ree

mile

s fr

om th

ree

mile

s pe

r hou

r).

OO

OO

Mea

sure

men

ts a

re a

lway

s lik

ely

to g

ive

slig

htly

diff

eren

t num

bers

, eve

n if

wha

t is

bein

g m

easu

red

stay

s th

e sa

me.

O

OF

B. S

ymbo

lic R

elat

ions

hips

Tabl

es a

nd g

raph

s ca

n sh

ow h

ow v

alue

s of

one

qua

ntity

are

rela

ted

to v

alue

s of

an

othe

r.F

OF

O

C. S

hape

s

Gra

phic

al d

ispl

ay o

f num

bers

may

mak

e it

poss

ible

to s

pot p

atte

rns

that

are

not

ot

herw

ise

obvi

ous,

such

as

com

para

tive

size

an

d tr

ends

.

FO

FF

D. U

ncer

tain

ty

Som

e pr

edic

tions

can

be

base

d on

wha

t is

kno

wn

abou

t the

pas

t, as

sum

ing

that

co

nditi

ons

are

pret

ty m

uch

the

sam

e no

w.

OO

O

E. R

easo

ning

One

way

to m

ake

sens

e of

som

ethi

ng is

to

thin

k ho

w it

is li

ke s

omet

hing

mor

e fa

mili

ar.

O

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Page 70: Solar Energy Field Trip

| ENERGY | bENChmaRks 2�4

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

B11

. Com

mon

The

mes

A. S

yste

ms

In s

omet

hing

that

con

sist

s of

man

y pa

rts,

the

part

s us

ually

influ

ence

one

ano

ther

.O

B. M

odel

s

Geo

met

ric fi

gure

s, nu

mbe

r seq

uenc

es,

grap

hs, d

iagr

ams,

sket

ches

, num

ber l

ines

, m

aps,

and

stor

ies

can

be u

sed

to re

pres

ent

obje

cts,

even

ts, a

nd p

roce

sses

in th

e re

al

wor

ld, a

lthou

gh s

uch

repr

esen

tatio

ns c

an

neve

r be

exac

t in

ever

y de

tail.

OO

OO

OO

OO

C. C

onst

ancy

and

Cha

nge

Thin

gs c

hang

e in

ste

ady,

repe

titiv

e, o

r irr

egul

ar w

ays-

or s

omet

imes

in m

ore

than

on

e w

ay a

t the

sam

e tim

e. O

ften

the

best

w

ay to

tell

whi

ch k

inds

of c

hang

e ar

e ha

ppen

ing

is to

mak

e a

tabl

e or

gra

ph o

f m

easu

rem

ents

.

OO

O

12. H

abit

s of

Min

d

A. V

alue

s an

d A

ttitu

des

Keep

reco

rds

of th

eir i

nves

tigat

ions

and

ob

serv

atio

ns a

nd n

ot c

hang

e th

e re

cord

s la

ter.

OO

OO

OO

OO

OO

OO

Offe

r rea

sons

for t

heir

findi

ngs

and

cons

ider

re

ason

s su

gges

ted

by o

ther

s.O

OO

OO

C. M

anip

ulat

ion

and

Obs

erva

tion

Keep

a n

oteb

ook

that

des

crib

es

obse

rvat

ions

mad

e, c

aref

ully

dis

tingu

ishe

s ac

tual

obs

erva

tions

from

idea

s an

d sp

ecul

atio

ns a

bout

wha

t was

obs

erve

d, a

nd

is u

nder

stan

dabl

e w

eeks

or m

onth

s la

ter.

OO

OO

OO

OO

OO

O

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

9 o

f 10)

Page 71: Solar Energy Field Trip

2��ENERGY | bENChmaRks |

LEG

END

: F=

Focu

s in

Les

son

O

=Ong

oing

Dev

elop

men

t

E=Ea

rly In

trod

uctio

nLE

SSO

N

BEN

CHM

ARK

12

34

56

78

9SB

A1

SBA

2SB

A3

SBA

4SR

BD

. Com

mun

icat

ion

Skill

s

Writ

e in

stru

ctio

ns th

at o

ther

s ca

n fo

llow

in

carr

ying

out

a p

roce

dure

.O

Mak

e sk

etch

es to

aid

in e

xpla

inin

g pr

oced

ures

or i

deas

.O

F

Use

num

eric

al d

ata

in d

escr

ibin

g an

d co

mpa

ring

obje

cts

and

even

ts.

OO

OO

O

Org

aniz

e in

form

atio

n in

sim

ple

tabl

es a

nd

grap

hs a

nd id

entif

y re

latio

nshi

ps th

ey

reve

al. (

Gra

des

6-8)

FF

O

Loca

te in

form

atio

n in

refe

renc

e bo

oks,

back

issu

es o

f new

spap

ers

and

mag

azin

es,

com

pact

dis

ks, a

nd c

ompu

ter d

atab

ases

. (G

rade

s 6-

8)

FO

E. C

ritic

al-R

espo

nse

Skill

s

Reco

gniz

e w

hen

com

paris

ons

mig

ht n

ot b

e fa

ir be

caus

e so

me

cond

ition

s ar

e no

t kep

t th

e sa

me.

OO

OF

Am

eric

an A

ssoc

iatio

n fo

r the

Adv

ance

men

t of S

cien

ce (P

roje

ct 2

061)

. Ben

chm

arks

for S

cien

ce L

itera

cy. N

ew Y

ork:

Oxf

ord

Uni

vers

ity P

ress

, 199

3.

Ben

chm

arks

(Page

10

of 1

0)

Page 72: Solar Energy Field Trip

Energy Unit Teacher Masters: Table of Contents

Introductory Letter to Families

Welcome to the Energy Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–2

Assessments

Energy Assessment 1: Energy Forms and Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Energy Assessment 2: Heat Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Energy Assessment 3: Energy Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Energy Assessment 4: Cooperative Group Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Energy Assessment 5: Planning and Designing an Invention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Energy Assessment 6: Recording and Analyzing Data and Making Conclusions . . . . . . . . . . . . . .8

Note Recording Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9–10

Teacher Masters

Request for Materials (Lessons 1, 4, and 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Energy Walk Reference Sheet (Lesson 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12–13

Identifying Energy Forms (Lesson 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Energy Station Directions (Lesson 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15–18

Identifying Energy Transfers (Lesson 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

How to Build a Balloon Boat (Lesson 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–21

How to Build a Rubber Band Boat (Lesson 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22–23

How to Build a Secret Potion Boat (Lesson 4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24–26

Consumer Math (Lesson 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27–29

Automatic Sunscreen Applicator and Alarm (Lesson 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30–31

Measuring Accurately (SBA 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Calibrating Thermometers (SBA 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–34

Graphing the Height of a Fern (SBA 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Setting Up a Fair Test (SBA 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36–39

Energy Unit Teacher Masters: Table of Contents, page 1 of 2

ISBN 1-59192-287-92 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 082009 Edition. Copyright © 2005 Chicago Science Group. All Rights Reserved.

Page 73: Solar Energy Field Trip

Energy Teacher Master 2

Family Links

Energy Log (Lesson 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Toy Box Science (Lesson 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Heat Energy Transfers (Lesson 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Kitchen Conductors (Lesson 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Criteria for Insulators (Lesson 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Insulator Scavenger Hunt (Lesson 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Is Your Home Energy-Efficient? (Lesson 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

My Invention (Lesson 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Energy Unit Teacher Masters: Table of Contents, page 2 of 2

Page 74: Solar Energy Field Trip

Energy Teacher Master 3Assessment 1: Energy Forms and Transfers

Energy Assessment 1: Energy Forms and TransfersAs you evaluate students’ discussions and work, determine how well they understand the following concepts.

Assessment Criteria:

Students’ Names

A. Energy is observable all around us and can take many forms.

B. Energy moves from place to place and sometimes changes forms to make things happen.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

Page 75: Solar Energy Field Trip

Energy Teacher Master 15Energy Station Directions (Lesson 3), page 1 of 4

Energy Station Directions

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 1: Pop-up Toy1. Press down gently on the toy’s head until the suction cup sticks to the base.

2. Watch and wait.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 2: Dominoes1. Line up the dominoes—with dominoes placed upright on their shortest end—

so that the space between every two dominoes is slightly less than the length of one domino.

2. Gently tap the first domino in the line so it falls in the direction of the second domino.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 3: Sparking Wheel1. Hold the stem of the toy between your index and middle fingers.

2. Pump the base several times with your thumb.

3. Observe what happens.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 4: Energy Ball1. Touch both metal strips on the ball at the same time.

2. Look and listen.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Page 76: Solar Energy Field Trip

Energy Teacher Master 16

Energy Station Directions

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 5: Hand-held Electrical Generator1. Hold the generator firmly in one hand.

2. Use your other hand to turn the crank handle.

3. Observe.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 6: Spinning Top1. Begin by looking at the top that has been taken apart. Can you make its light

turn on?

2. Now look at the top that has not been taken apart. Fit the top into its base so there is no gap between the two pieces.

3. Twist the base clockwise four times.

4. Hold the top upright (with the button on top) slightly above the center of the box lid and push the button to release the top.

5. Watch what happens. How do you explain what you see?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 7: Radiometer1. Place the radiometer on a flat surface under a light source.

2. What happens?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Energy Station Directions (Lesson 3), page 2 of 4

Page 77: Solar Energy Field Trip

Energy Teacher Master 17Energy Station Directions (Lesson 3), page 3 of 4

Energy Station Directions

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 8: Ball1. Hold the ball in your hand at about waist level.

2. Drop the ball.

3. Catch the ball. (This is a very important step!)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 8 (alternative): Pull-back Toy Car1. Hold the car in one hand and place the wheels on a flat, level surface.

2. Pull the car backwards about 1/2 meter, or until you hear a clicking sound. DO NOT OVERWIND.

3. Release and observe.

Page 78: Solar Energy Field Trip

Energy Teacher Master 18Energy Station Directions (Lesson 3), page 4 of 4

Energy Station Directions

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Station 9: Magic Bracelet1. Place your hands in the paper bag and slip the beaded bracelet onto your wrist.

2. Remove your hand from the bag and notice how the bracelet looks.

3. Position your wrist so that sunlight or the clamp light shines on the bracelet. Keep your hand a safe distance from the clamp light to prevent burns.

4. Look carefully at the beads on the bracelet. What is happening?

5. Place the bracelet back in the paper bag for the next group.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

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Name: Date:

Energy Teacher Master 41Family Link: Toy Box Science (Lesson 3)

Family Link with Science—Homework

Toy Box ScienceToday in class you mapped the energy transfers that occurred when you operated several different toys. Now think about your own toys. Do any of them require an energy transfer in order to work?

Select a toy that runs as a result of energy transfers and answer the following questions.

1. What is your toy called? _________________________________________

2. What does your toy do? _________________________________________

_____________________________________________________________

3. Describe, or use arrows to map, how energy is transferred to operate your toy.

Bonus Activity “Wintergreens in the Dark”1. Bring wintergreen-flavored Lifesavers® for you and a friend or family member

into a dark room such a closet. Allow your eyes to adjust to the dark. Look carefully at each other’s mouths as you both chew your Lifesaver. Use the space below to describe what happened.

2. Describe the energy transfer(s) that took place as you chewed the Lifesaver.

Please return to class by ____________________________.

Page 80: Solar Energy Field Trip

Energy Unit Visuals: Table of Contents

Overhead Transparencies

Energy Talk (Lesson 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Energy Cards (Lesson 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–3

Mapping Energy Transfers (Lessons 3 and 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Exploring How Well Different Materials Slow Heat Energy Transfer (Lesson 7) . . . . . . . . . . . . . . . .5

100W and 25W Light Bulbs (Lesson 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

25W and 26W Light Bulbs (Lesson 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

100W and 26W Light Bulbs (Lesson 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Automatic Sunscreen Applicator and Alarm (Lesson 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9–10

Comparing Graphs (SBA 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Graphing the Height of a Fern (SBA 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Photo Cards

Photo “Energy” Cards (Lesson 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13–28

ISBN 1-59192-288-7 2 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 08 2009 Edition. Copyright © 2005 Chicago Science Group. All Rights Reserved.

Page 81: Solar Energy Field Trip

2009 Edition. Copyright © 2005 Chicago Science Group. All Rights Reserved.www.sciencecompanion.com

Mapping Energy TransfersDemonstration:

Use arrows and words to show what types of energy transfers occurred as your teacher

operated the item listed above.

Energy Forms

Electrical  Chemical  Motion  Elastic  Gravitational  Heat  Light  Sound

Overhead Transparency: Mapping Energy Transfers (Lessons 3 and 4)

Energy Visual 4

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ENERGY | TABLE OF CONTENTS| 3

Table of ContentsIntroduction

Assessment Philosophy........................................................................ 5 Assessment Materials........................................................................... 8

Content Rubrics and Opportunity OverviewsEnergy Forms and Transfers Rubric 1................................................16 Energy Forms and Transfers Opportunities Overview........................17 Heat Energy Rubric 2..........................................................................18 Heat Energy Opportunities Overview..................................................19 Energy Efficiency Rubric 3..................................................................20 Energy Efficiency Opportunities Overview..........................................21

Skills and Attitudes Checklists and Self-AssessmentsCooperative Group Work: Checklist....................................................24 Working in a Group: Self-Assessment ................................................25 Recording and Analyzing Data and Making Conclusions: Checklist ..26 Collecting Data and Making Conclusions: Self-Assessment ..............27 Planning and Designing an Invention: Checklist.................................28

Performance Tasks and Evaluation Guidelines What is Energy? Cluster (Lessons 1-2): Lighting Up the Sky ....................................................................30 Energy Transfers Cluster (Lessons 3-4): Johnnie’s Bat ..............................................................................31 Riding Bikes................................................................................32 Heat Energy Transfers Cluster (Lessons 5-7): Hot Chocolate.............................................................................33 Baking Cookies...........................................................................34 What to Wear?............................................................................35 Applying Energy Smarts Transfers Cluster (Lessons 8-9): Household Lighting.....................................................................36 Unit Assessment: Chain Reaction Invention ...........................................................37

Quick Check Items and Answer KeysWhat is Energy? Cluster (Lessons 1-2) ..............................................40 Energy Transfers Cluster (Lessons 3-4) .............................................41 Heat Energy Transfers Cluster (Lessons 5-7) ....................................43 Applying Energy Smarts (Lessons 8-9) ..............................................46

Assessment Masters What is Energy? Cluster: Lighting Up the Sky ....................................................................50 Quick Check Items .....................................................................51

Page 83: Solar Energy Field Trip

4 | ENERGY | TABLE OF CONTENTS

Energy Transfers Cluster: Johnnie’s Bat ..............................................................................52 Riding Bikes................................................................................53 Quick Check Items .....................................................................54 Heat Energy Transfers Cluster: Hot Chocolate.............................................................................56 Baking Cookies...........................................................................57 What to Wear?............................................................................58 Quick Check Items .....................................................................59 Applying Energy Smarts Cluster: Household Lighting.....................................................................62 Quick Check Items .....................................................................63

Page 84: Solar Energy Field Trip

16 | ENERGY | CONTENT RUBRICS AND OPPORTUNITIES OVERVIEWS

Rubric 1: Energy Forms and Transfers Criterion A(Lessons 1—2, 9)

Criterion B(Lessons 3 4, 9)

Energy is observable all around us and can take many forms.

Energy moves from place to place and sometimes changes forms to make things happen.

4 - Exceeds Expectations

Explores content beyond the level presented in the lessons.

Understands at a secure level (see box below) and can give examples of objects that possess more than one form of energy.

Understands at a secure level (see box below) and can apply their understanding to new situations (e.g., toys brought from home, improvements on boats).

3 - Secure(MeetsExpectations)

Understands content at the level presented in the lessons and does not exhibit misconceptions.

Can identify many specific forms of energy in their environment.

Recognizes that energy moves from place to place and sometimes changes form to make things happen.

2 - Developing(Approaches Expectations)

Shows an increasing competency with lesson content.

Intuitively knows that certain objects have energy but doesn’t identify the energy as any specific form.

Has an incomplete understanding of how energy transfers make something happen(e.g., knows that energy transfers but not that sometimes energy changes form)

1 - Beginning

Has no previous knowledge of lesson content.

Cannot observe or identify energy in one’s surroundings.

Does not know that energy is required to make things happen.

Page 85: Solar Energy Field Trip

ENERGY | CONTENT RUBRICS AND OPPORTUNITIES OVERVIEWS | 17

Opportunities Overview: Energy Forms and Transfers

This table highlights opportunities to assess the criteria on Rubric 1: Energy Forms and Transfers. It does not include every assessment opportunity; feel free to select or devise other ways to assess various criteria.

Criterion A(Lessons 1—2, 9)

Criterion B(Lessons 3—4, 9)

Pre

and

Form

ativ

e O

ppor

tuni

ties

Lesson 1:- Journal writing - Reflective discussion

Lesson 2: - Teacher Master “Identifying Energy Forms”

- Synthesizing discussion Lesson 9:

- Exploration, Session 2 - Journal writing

Lesson 3:- Introductory discussion - Exploration - Science notebook pages 4–13 - Family Link “Toy Box Science” - Journal writing

Lesson 4: - Science notebook page 15

Lesson 9:- Exploration, Session 2 - Journal writing

Performance Tasks

What Is Energy? ClusterLighting Up the Sky, page 30

Unit Assessment Chain Reaction Invention, page 37

Energy Transfers Cluster Johnnie’s Bat, page 31 Riding Bikes, page 32

Unit Assessment Chain Reaction Invention, page 37

Quick Check Items

Sum

mat

ive

Opp

ortu

nitie

s

What Is Energy? ClusterPage 40: items 1, 2

Heat Energy Transfers ClusterPage 43: item 1

Energy Transfers ClusterPages 41-42: items 1-5

Page 86: Solar Energy Field Trip

ENERGY | PERFORMANCE TASK EVALUATION GUIDELINES | 31

Johnnie’s Bat Energy Transfers Cluster (Lesson 3-4)

Each year, Mr. Dracula throws a Halloween party. He asks every student to bring a toy to share. This year, Johnnie’s flying bat was the hit of the party. When he arrived at Mr. Dracula’s classroom, he hung the bat from the center of the ceiling with a piece of string. Once turned on (it ran on batteries), the bat flew around in circles, flashed its lit up red eyes, and screeched loudly.

After several flashing and screeching events, the string broke and the bat crashed to the floor.

Use words from the word bank and arrows to map what types of energy transfers occurred with Johnnie’s bat.

TEACHER NOTES:Use this assessment after teaching Lesson 3.

You might encourage your students to use different kinds of lines to represent two different maps. For example, they could use a solid line for the flying bat and a dotted line for the falling bat. They could also use different colors—one for the flying bat and one for the falling bat.

EVALUATION GUIDELINES:When evaluating student answers, consider whether they include some of the following elements in their written explanations:

There are many different energy transfers taking place at the same time. For example, when the bat is flying, chemical energy (from battery) transfers to motion energy (bat flying), light energy (eye’s flashing), and sound energy (bat screeching). When the bat falls, gravitational energy transfers to motion energy and possibly ends with sound energy (as it hits the floor).

Energy Forms electrical chemical motion elastic gravitational heat light sound

motion

chemical

light sound

gravitational

Page 87: Solar Energy Field Trip

32 | ENERGY | PERFORMANCE TASK EVALUATION GUIDELINES

Riding Bikes Energy Transfers Cluster (Lessons 3-4)

Hallie loves riding bikes. She loves how she can pedal really hard to go fast, or not pedal at all, and just gently coast along. She loves being in control of how long it takes her to get somewhere. Hallie thinks of her bike as one of the most amazing machines because it uses no energy to get her from place to place.

Do you agree with Hallie that a bike is a machine? Explain your answer.

Do you agree that it uses no energy? Explain your reasoning.

TEACHER NOTE:Use this assessment after teaching Lesson 4.

EVALUATION GUIDELINES:When evaluating student answers, consider whether they include the following elements in their written explanations:

Yes, the bike is a machine.

The bike does use energy because a bike could not move without energy transfers. All change requires energy.

Muscles or bodies use chemical energy (from the food we eat) and transfers it to the motion energy of our legs to make the bike move. Bikes on a hill or slope have gravitational energy that transfers to motion energy when a bike coasts downhill. All of these transfers help Hallie get from one place to another.

Page 88: Solar Energy Field Trip

ENERGY | QUICK CHECK ANSWER KEYS | 41

Energy Transfers Cluster Quick Check Items

TEACHER NOTE: The following questions relate to the Energy Transfers cluster. Use them after teaching the entire cluster, or select the applicable questions immediately following each lesson. You can also compile Quick Check items into an end-of-unit assessment.

1. (Lesson 3) True or False? If false, rewrite the statements to make them true.

a. Energy is required for change to happen. ___________ true

b. Energy cannot move from place to place. ___________ false

Energy moves from place to place, or object to object, all of the time.

2. (Lesson 3) Which sequence best describes the energy transfers in a solar propeller?

a. light chemical sound

b. light chemical motion

c. light electrical motion

d. no transfers take place

3. (Lesson 3) In question 2, what happened to the energy during each transfer?

a. The energy changed form as it transferred.

b. Nothing happened. The energy form stayed the same.

c. The energy moved but did not change forms.

4. (Lesson 4) Put an “X” next to any item that is a machine.

X_______ car

X_______ rowboat

X_______ scissors

X_______ lamp

Page 89: Solar Energy Field Trip

Date:

Hello Scientist,

Welcome to the Energy unit. This notebook is your place to

record discoveries about energy. Like all scientists, you will

wonder, think, try, observe, record, and discover. As you do

so, it is important to keep a record of your work. Your ques-

tions, investigations, answers, and reflections can then be

shared and returned to at any time.

We know much about science, but there is much more to be

learned. Your contributions start here.

Enjoy, take pride in, and share your discoveries—science

depends on scientists like you!

ISBN 1-59192-285-2

2 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 08

2009 Edition. Copyright © 2005 Chicago Science Group. All Rights Reserved.

Hello Scientist

ANNOTATED TEACHER GUIDE

Teacher Guide Annotations supplied in RED for ease of use.

ISBN 1-59192-286-0

2 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 08

2009 Edition. Copyright © 2005 Chicago Science Group. All Rights Reserved.

Page 90: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Demonstration: Solar Propeller

Use arrows and words to show what types of energy transfers occurred as your teacher oper-ated the item listed above.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Students can start their map from any star on the page.

light

electrical

motion

light energy from the sun hits the solar panel

electrical energy powers the motor, making the propeller spin

Page 91: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Pop-up toy

Example responses for each toy station are included on the following pages, although the students will not necessarily complete the stations in the order presented in this guide.

motion

elastic

motion

hand moves and pushes down on pop-up toy to store elastic energy

the spring in the pop-up toy extends, making the toy move and pop into the air

Page 92: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

motion

motion

gravitational

hand knocks down domino

domino falls

Dominoes

motion

falling domino hits next domino

Page 93: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Sparking-wheel

motion

motion

heat

hand pumps wheel

surfaces in toy rub against each other

light

tiny glowing pieces of the surfaces fly off as “sparks”

Page 94: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

chemical

electrical

light

connection of electrical circuit allows chemical energy from the battery to transfer to electrical energy

electricity makes ball light up

Energy ball

sound

electricity creates sound

Page 95: Solar Energy Field Trip

Date:

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Hand-held electrical generator

motion

electrical

light

hand turns crank, generating an electrical current

electricity makes the bulb light up

gears rub together as crank handle is turned

sound

Page 96: Solar Energy Field Trip

Date:

�0

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

motion

elastic

motion

top is twisted

top is released and spins

Spinning top

light

spinning causes top to light up

There is a chemical energy to electrical energy component in the spinning top. The spinning causes the battery’s electrodes to connect, which transfers the battery’s chemical energy to electrical energy and then to light energy. However, students may not identify all of these energy transfers.

Page 97: Solar Energy Field Trip

Date:

��

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Radiometer

light

heat

motion

black surfaces absorb heat

top spins

Page 98: Solar Energy Field Trip

Date:

��

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

gravitational

motion

elastic

ball is dropped

ball hits floor

Ball

motion

ball bounces up

Page 99: Solar Energy Field Trip

Date:

��

Mapping Energy Transfers

Type of Toy:

Use arrows and words to show how energy was transferred in this toy. You can use as many of the shapes as you need for your map. You can also draw more shapes if you need them.

Energy Forms

Electrical Chemical Motion Elastic Gravitational Heat Light Sound

Mapping Energy Transfers (Lesson 3)

Magic bracelet

light

chemical

light energy from the sun hits the beads, making them change color

Page 100: Solar Energy Field Trip

EnergyStudent Reference Book

Page 101: Solar Energy Field Trip

Writers

Belinda Basca and Martha Sullivan

Developers

Colleen Bell, Diane Bell, Cindy Buchenroth-Martin, and Catherine Grubin

Editors

Rachel Burke and Wanda Gayle

Pedagogy and Content Advisors

Jean Bell, Max Bell, Nick Cabot*, Debbie Clement*, Josie Grotenhuis*, Tim Strains*, and Robert Ward

*Scientists or teachers who gave advice but are not part of the Chicago Science Group.

Field Test Teachers

Joyce Berry, Suze Bodwell, Jim Elwell, Nancy Florig, David Grelecki, Matt Laughlin, Lisette Mirabile,

Valerie Powell, Jen Ryan, Chris Sanborn, Kitty Skow, Jane Stephenson, Will Whitlock, and Nancy Zordan

Book Design and Production

Happenstance Type-O-Rama; Picas & Points, Plus (Carolyn Loxton)

www.sciencecompanion.com

2009 Edition

Copyright © 2005 Chicago Science Group.

All Rights Reserved

Printed in the United States of America. Except as permitted under the United States Copyright Act, no

part of this publication may be reproduced or distributed in any form or by any means or stored in a

database or retrieval system without the prior written permission of the publisher.

SCIENCE COMPANION®, EXPLORAGEAR®, the CROSSHATCH Design™ and the WHEEL

Design® are trademarks of Chicago Science Group and Chicago Educational Publishing.

ISBN 1-59192-397-2

2 3 4 5 6 7 8 9 10-P001-17 16 15 14 13 12 11 10 09 08

Table of Contents

Chapter 1: Recognizing Forms of Energy . . . . . . . . . . . . . . . . . . . . . . . . . 1

Where Can You Find Energy? . . . . . . . . . . . . . . . . . . . . 1

Forms of Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Motion Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chemical Energy . . . . . . . . . . . . . . . . . . . . . . . . . 3

Gravitational Energy. . . . . . . . . . . . . . . . . . . . . . . 4

Elastic Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Heat Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Light Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Electrical Energy . . . . . . . . . . . . . . . . . . . . . . . . . 8

Sound Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Energy Makes Things Happen . . . . . . . . . . . . . . . . . . 10

Chapter 2: Recognizing Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . .13

Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Energy Transfers and the Natural World . . . . . . . . . . . . . 14

Energy Transfers from the Sun. . . . . . . . . . . . . . . . . 14

Energy Transfers from Inside the Earth . . . . . . . . . . . . 17

Energy Transfers Between Living Things . . . . . . . . . . . 19

Frequently Asked Questions. . . . . . . . . . . . . . . . . . . . 21

Does Energy Change When It Is Transferred? . . . . . . . . . 21

How Can I Tell That Energy Is Being Transferred in the Natural World? . . . . . . . . . . . . . . . . . . . . 22

Page 102: Solar Energy Field Trip

Table of Contents

Chapter 1: Recognizing Forms of Energy . . . . . . . . . . . . . . . . . . . . . . . . . 1

Where Can You Find Energy? . . . . . . . . . . . . . . . . . . . . 1

Forms of Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Motion Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chemical Energy . . . . . . . . . . . . . . . . . . . . . . . . . 3

Gravitational Energy. . . . . . . . . . . . . . . . . . . . . . . 4

Elastic Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Heat Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Light Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Electrical Energy . . . . . . . . . . . . . . . . . . . . . . . . . 8

Sound Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Energy Makes Things Happen . . . . . . . . . . . . . . . . . . 10

Chapter 2: Recognizing Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . .13

Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Energy Transfers and the Natural World . . . . . . . . . . . . . 14

Energy Transfers from the Sun. . . . . . . . . . . . . . . . . 14

Energy Transfers from Inside the Earth . . . . . . . . . . . . 17

Energy Transfers Between Living Things . . . . . . . . . . . 19

Frequently Asked Questions. . . . . . . . . . . . . . . . . . . . 21

Does Energy Change When It Is Transferred? . . . . . . . . . 21

How Can I Tell That Energy Is Being Transferred in the Natural World? . . . . . . . . . . . . . . . . . . . . 22

iii

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iv

Chapter 3: Putting Energy Transfers to Use . . . . . . . . . . . . . . . . . . . . . . .25

Machines and Energy Transfers . . . . . . . . . . . . . . . . . . 26

Floating Machines—Boats and Energy Transfers . . . . . . . . . 28

How Do Boats Transfer Energy to Carry People and Things Across Water? . . . . . . . . . . . . . . . . . . . . 28

Machines of Today and Yesterday. . . . . . . . . . . . . . . . . 30

Household Chores in the 18th Century . . . . . . . . . . . . . . 31

Testing Your Energy IQ . . . . . . . . . . . . . . . . . . . . . . 36

Chapter 4: Heat Energy and Temperature—What’s the Difference? . . . . . . .39

Temperature and Heat Energy . . . . . . . . . . . . . . . . . . 39

How a Thermometer Works . . . . . . . . . . . . . . . . . . . . 41

Thermometers Are All Around You . . . . . . . . . . . . . . 41

How a Bulb Thermometer Works . . . . . . . . . . . . . . . 42

Temperature Scales . . . . . . . . . . . . . . . . . . . . . . 43

Chapter 5: Heat Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Identifying Heat Energy Transfers. . . . . . . . . . . . . . . . . 45

Heat Energy Transfers from Warmer to Cooler Objects. . . . . . 50

Chapter 6: Conductors of Heat Energy . . . . . . . . . . . . . . . . . . . . . . . . . .57

Kitchen Conductors . . . . . . . . . . . . . . . . . . . . . . . . 57

Scientific Inventions in Your Kitchen! . . . . . . . . . . . . . 57

Cooking—Harnessing Heat Energy Transfers to Meet Our Needs . . . . . . . . . . . . . . . . . . . . . . . 62

How Well Do Materials Conduct Heat Energy? . . . . . . . . 63

Chapter 7: Insulation to Keep Us Warm . . . . . . . . . . . . . . . . . . . . . . . . .69

Insulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

The Many Types of Insulators . . . . . . . . . . . . . . . . . 69

How Homes Stay Warm . . . . . . . . . . . . . . . . . . . . . . 70

Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

The Dangers of Fiberglass . . . . . . . . . . . . . . . . . . . 73

Alternatives to Fiberglass . . . . . . . . . . . . . . . . . . . 74

How Humans Stay Warm . . . . . . . . . . . . . . . . . . . . . 75

Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Layer Up! . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

How Animals Stay Warm . . . . . . . . . . . . . . . . . . . . . 76

Hair Traps Air . . . . . . . . . . . . . . . . . . . . . . . . . 76

Blubber or Fat . . . . . . . . . . . . . . . . . . . . . . . . . 78

Down Feathers . . . . . . . . . . . . . . . . . . . . . . . . . 80

Chapter 8: Using Energy Efficiently . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

What Makes Something Energy-Efficient? . . . . . . . . . . . . 83

Automobiles and Energy Efficiency . . . . . . . . . . . . . . 83

Household Appliances and Energy Efficiency . . . . . . . . . 84

Light Bulbs and Energy Efficiency . . . . . . . . . . . . . . . 86

Chapter 9: Why Energy Efficiency Matters . . . . . . . . . . . . . . . . . . . . . . . .95

Why Is It Important to Use Things that Are Energy-Efficient? . . 95

Using Energy-Efficient Machines Saves You Money! . . . . . 95

Using Energy-Efficient Things Means Our Energy Resources Will Last Longer! . . . . . . . . . . . . . . . . . 97

Using Energy-Efficient Machines Means a Healthier Planet!. . . . . . . . . . . . . . . . . . . . . . . 98

How Else Can We Use Energy Wisely?. . . . . . . . . . . . . . .102

Using Renewable Energy Sources . . . . . . . . . . . . . . .102

Energy Sources—Pros and Cons . . . . . . . . . . . . . . . .107

Thinking “Green” When Building. . . . . . . . . . . . . . .109

How Can I Be Energy-Efficient? . . . . . . . . . . . . . . . . . .110

Some Easy Things You Can Do . . . . . . . . . . . . . . . .110

Table of Contents

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v

Chapter 3: Putting Energy Transfers to Use . . . . . . . . . . . . . . . . . . . . . . .25

Machines and Energy Transfers . . . . . . . . . . . . . . . . . . 26

Floating Machines—Boats and Energy Transfers . . . . . . . . . 28

How Do Boats Transfer Energy to Carry People and Things Across Water? . . . . . . . . . . . . . . . . . . . . 28

Machines of Today and Yesterday. . . . . . . . . . . . . . . . . 30

Household Chores in the 18th Century . . . . . . . . . . . . . . 31

Testing Your Energy IQ . . . . . . . . . . . . . . . . . . . . . . 36

Chapter 4: Heat Energy and Temperature—What’s the Difference? . . . . . . .39

Temperature and Heat Energy . . . . . . . . . . . . . . . . . . 39

How a Thermometer Works . . . . . . . . . . . . . . . . . . . . 41

Thermometers Are All Around You . . . . . . . . . . . . . . 41

How a Bulb Thermometer Works . . . . . . . . . . . . . . . 42

Temperature Scales . . . . . . . . . . . . . . . . . . . . . . 43

Chapter 5: Heat Energy Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Identifying Heat Energy Transfers. . . . . . . . . . . . . . . . . 45

Heat Energy Transfers from Warmer to Cooler Objects. . . . . . 50

Chapter 6: Conductors of Heat Energy . . . . . . . . . . . . . . . . . . . . . . . . . .57

Kitchen Conductors . . . . . . . . . . . . . . . . . . . . . . . . 57

Scientific Inventions in Your Kitchen! . . . . . . . . . . . . . 57

Cooking—Harnessing Heat Energy Transfers to Meet Our Needs . . . . . . . . . . . . . . . . . . . . . . . 62

How Well Do Materials Conduct Heat Energy? . . . . . . . . 63

Chapter 7: Insulation to Keep Us Warm . . . . . . . . . . . . . . . . . . . . . . . . .69

Insulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

The Many Types of Insulators . . . . . . . . . . . . . . . . . 69

How Homes Stay Warm . . . . . . . . . . . . . . . . . . . . . . 70

Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

The Dangers of Fiberglass . . . . . . . . . . . . . . . . . . . 73

Alternatives to Fiberglass . . . . . . . . . . . . . . . . . . . 74

How Humans Stay Warm . . . . . . . . . . . . . . . . . . . . . 75

Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Layer Up! . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

How Animals Stay Warm . . . . . . . . . . . . . . . . . . . . . 76

Hair Traps Air . . . . . . . . . . . . . . . . . . . . . . . . . 76

Blubber or Fat . . . . . . . . . . . . . . . . . . . . . . . . . 78

Down Feathers . . . . . . . . . . . . . . . . . . . . . . . . . 80

Chapter 8: Using Energy Efficiently . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

What Makes Something Energy-Efficient? . . . . . . . . . . . . 83

Automobiles and Energy Efficiency . . . . . . . . . . . . . . 83

Household Appliances and Energy Efficiency . . . . . . . . . 84

Light Bulbs and Energy Efficiency . . . . . . . . . . . . . . . 86

Chapter 9: Why Energy Efficiency Matters . . . . . . . . . . . . . . . . . . . . . . . .95

Why Is It Important to Use Things that Are Energy-Efficient? . . 95

Using Energy-Efficient Machines Saves You Money! . . . . . 95

Using Energy-Efficient Things Means Our Energy Resources Will Last Longer! . . . . . . . . . . . . . . . . . 97

Using Energy-Efficient Machines Means a Healthier Planet!. . . . . . . . . . . . . . . . . . . . . . . 98

How Else Can We Use Energy Wisely?. . . . . . . . . . . . . . .102

Using Renewable Energy Sources . . . . . . . . . . . . . . .102

Energy Sources—Pros and Cons . . . . . . . . . . . . . . . .107

Thinking “Green” When Building. . . . . . . . . . . . . . .109

How Can I Be Energy-Efficient? . . . . . . . . . . . . . . . . . .110

Some Easy Things You Can Do . . . . . . . . . . . . . . . .110

Table of Contents

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Table of Contentsvi

Chapter 10: The Spirit of Invention . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Getting Energy to Work for You . . . . . . . . . . . . . . . . . .113

What Does It Take to Be an Inventor? . . . . . . . . . . . . . .114

The Inventive Mind . . . . . . . . . . . . . . . . . . . . . . . .120

Thinking Like an Inventor . . . . . . . . . . . . . . . . . . . .121

Chapter 11: Graphs—Part of a Scientist’s Toolbox . . . . . . . . . . . . . . . . . . 123

Finding the Right Tool for the Job. . . . . . . . . . . . . . . . .123

Bar Graphs . . . . . . . . . . . . . . . . . . . . . . . . . . .123

Line Graphs . . . . . . . . . . . . . . . . . . . . . . . . . .125

Reading Graphs . . . . . . . . . . . . . . . . . . . . . . . . . .128

Appendix A: A Walk Through Energy History . . . . . . . . . . . . . . . . . . . . . . 129

Appendix B: Automatic Sunscreen Applicator and Alarm . . . . . . . . . . . . . . 147

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

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��

Recognizing Energy Transfers

Energy Transfers

Every time something happens energy is involved. In fact, it

is the movement of energy from one object to another, one

form to another, or one place to another that brings about all

change. Scientists use the term energy transfer to describe

the movement of energy.

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Chapter ���

Energy Transfers and the Natural World

Energy transfers are a natural part of our world.

Energy Transfers from the Sun

Energy FactThe Earth receives

only half a billionth

of the energy that

leaves the sun.

As the third planet from the sun, the Earth receives a steady

supply of energy from the sun.

The transfer of energy from the sun to the Earth is responsible

for many of the changes that take place around us.

Weather changes…

The Sun and Its Energy Transfers—The Source of All Weather

Weather Facts• Millions of tons of

water vapor are

evaporated into

the air daily.

• Even the “cleanest”

air found on Earth

contains about

1000 dust particles

per cubic meter

of air.

• About one million

cloud droplets are

contained in one

drop of rain.

• Clouds and precipitation As the sun heats up the

Earth’s waters, some water evaporates and rises into the

atmosphere. Eventually, it cools and condenses on tiny dust

particles to form clouds. The size of the droplets grows until

they are so large that they fall as precipitation.

• Wind The sun does not heat all parts of the Earth equally.

The areas around the equator—the tropics—receive more of

the sun’s energy and are warmer than other parts of the Earth.

Unequal heating leads to the movement of air—wind—from

cooler (higher pressure) regions to warmer (lower pressure)

regions.

• Storms Storms such as hurricanes also result from the

transfer of the sun’s energy to Earth. As large bodies of water

are warmed by the sun, more and more of their water evap-

orates and eventually condenses in the air above. A huge

amount of energy is released into the air as this occurs. The

released energy sets the air in motion, spinning it faster and

wider until a hurricane forms.

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��Recognizing Energy Transfers

Energy Transfers and the Natural World

Energy transfers are a natural part of our world.

Energy Transfers from the Sun

Energy FactThe Earth receives

only half a billionth

of the energy that

leaves the sun.

As the third planet from the sun, the Earth receives a steady

supply of energy from the sun.

The transfer of energy from the sun to the Earth is responsible

for many of the changes that take place around us.

Weather changes…

The Sun and Its Energy Transfers—The Source of All Weather

Weather Facts• Millions of tons of

water vapor are

evaporated into

the air daily.

• Even the “cleanest”

air found on Earth

contains about

1000 dust particles

per cubic meter

of air.

• About one million

cloud droplets are

contained in one

drop of rain.

• Clouds and precipitation As the sun heats up the

Earth’s waters, some water evaporates and rises into the

atmosphere. Eventually, it cools and condenses on tiny dust

particles to form clouds. The size of the droplets grows until

they are so large that they fall as precipitation.

• Wind The sun does not heat all parts of the Earth equally.

The areas around the equator—the tropics—receive more of

the sun’s energy and are warmer than other parts of the Earth.

Unequal heating leads to the movement of air—wind—from

cooler (higher pressure) regions to warmer (lower pressure)

regions.

• Storms Storms such as hurricanes also result from the

transfer of the sun’s energy to Earth. As large bodies of water

are warmed by the sun, more and more of their water evap-

orates and eventually condenses in the air above. A huge

amount of energy is released into the air as this occurs. The

released energy sets the air in motion, spinning it faster and

wider until a hurricane forms.

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Chapter ���

…and plants grow

Photosynthesis— How the Transfer of Energy from the Sun Feeds the Planet

Almost all living things depend on food created by green plants.

Green plants contain a special pigment (a colored substance) that

captures the sun’s energy. Plants use this energy (light energy) to

create food (chemical energy). The transfer of energy from sun-

light to plant food is called photosynthesis. Plants use the food

they create to grow. When other organisms eat plants, the chemi-

cal energy from the plants is transferred to them.

Energy Transfers from Inside the Earth

Energy is also transferred from deep within the earth’s piping

hot center (4300° C to 7200° C), causing changes that we see

on the surface, such as earthquakes and volcanic eruptions.

These changes are so dramatic that it is very obvious that

energy is being transferred. Heat energy from deep within the

earth is being transferred to the motion energy that literally

“shakes” our world.

0 km(0 mi)

1228 km(763 mi)

3500 km(2174 mi)

6340 km(3939 mi)

6378 km(3963 mi)

Inner Core 4300C to

7200C(7772F to12992F) Mantle

870C to 3700C(1598F to

6692F)

Outer Core3700C to 4300C(6692F to 7772F)

CrustAir Temperature

to 870C(1598F)

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��Recognizing Energy Transfers

…and plants grow

Photosynthesis— How the Transfer of Energy from the Sun Feeds the Planet

Almost all living things depend on food created by green plants.

Green plants contain a special pigment (a colored substance) that

captures the sun’s energy. Plants use this energy (light energy) to

create food (chemical energy). The transfer of energy from sun-

light to plant food is called photosynthesis. Plants use the food

they create to grow. When other organisms eat plants, the chemi-

cal energy from the plants is transferred to them.

Energy Transfers from Inside the Earth

Energy is also transferred from deep within the earth’s piping

hot center (4300° C to 7200° C), causing changes that we see

on the surface, such as earthquakes and volcanic eruptions.

These changes are so dramatic that it is very obvious that

energy is being transferred. Heat energy from deep within the

earth is being transferred to the motion energy that literally

“shakes” our world.

0 km(0 mi)

1228 km(763 mi)

3500 km(2174 mi)

6340 km(3939 mi)

6378 km(3963 mi)

Inner Core 4300C to

7200C(7772F to12992F) Mantle

870C to 3700C(1598F to

6692F)

Outer Core3700C to 4300C(6692F to 7772F)

CrustAir Temperature

to 870C(1598F)

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Chapter ���

Heat Transfer from Earth’s Core— The Driving Force Behind Earthshaking Events

The center of the earth—its core—is very, very hot! Heat energy

is transferred from the core out towards the earth’s surface. This

heat energy makes a layer of rock beneath the surface—the lower

mantle—so hot that it is semi-molten (able to flow slowly). The

earth’s crust (the thin surface layer of the earth that we walk on)

and solid upper mantle rest on the semi-molten lower mantle. As

the lower mantle slowly flows, shifts occur above it. When there

are big shifts, earthquakes happen.

A fracture (crack) in the ground caused by an earthquake.

Volcanic eruptions are also the result of heat transfers from earth’s

core. When heat from the core is transferred to rock beneath the

earth’s surface, the rock melts. Periodically, this melted (molten)

rock escapes out of cracks in the earth’s surface, sometimes explo-

sively, as when a volcanic eruption occurs.

Lava erupting from a volcano.

Energy Transfers Between Living Things

Some energy transfers happen so slowly, or on such a small

scale, it is hard to see them at all. For example, logs slowly

decompose as their chemical energy transfers to the living

organisms—mushrooms, bacteria, and worms—that feed on it.

For a large log, this can take decades.

A decomposing log.

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��Recognizing Energy Transfers

Heat Transfer from Earth’s Core— The Driving Force Behind Earthshaking Events

The center of the earth—its core—is very, very hot! Heat energy

is transferred from the core out towards the earth’s surface. This

heat energy makes a layer of rock beneath the surface—the lower

mantle—so hot that it is semi-molten (able to flow slowly). The

earth’s crust (the thin surface layer of the earth that we walk on)

and solid upper mantle rest on the semi-molten lower mantle. As

the lower mantle slowly flows, shifts occur above it. When there

are big shifts, earthquakes happen.

A fracture (crack) in the ground caused by an earthquake.

Volcanic eruptions are also the result of heat transfers from earth’s

core. When heat from the core is transferred to rock beneath the

earth’s surface, the rock melts. Periodically, this melted (molten)

rock escapes out of cracks in the earth’s surface, sometimes explo-

sively, as when a volcanic eruption occurs.

Lava erupting from a volcano.

Energy Transfers Between Living Things

Some energy transfers happen so slowly, or on such a small

scale, it is hard to see them at all. For example, logs slowly

decompose as their chemical energy transfers to the living

organisms—mushrooms, bacteria, and worms—that feed on it.

For a large log, this can take decades.

A decomposing log.

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Chapter ��0

The Food Chain— Energy Transfers Between Living Things

The transfer of energy from one organism to another is called

a food chain. Food chains show how energy is passed from

one organism to another. The arrows between the organisms

show the direction of energy flow. The plant is eaten by the

mouse; the mouse is eaten by the snake; the snake is eaten by

the hawk.

An example of a food chain.

Frequently Asked Questions

Does Energy Change When It Is Transferred?

• Sometimes energy changes form when it is transferred.

For example, when sunlight falls on green plants, energy

is transferred from light to chemical energy.

• Other times energy moves but does not change form.

When a spoon is placed in a bowl of soup, heat energy is

transferred up the spoon handle without changing form.

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��Recognizing Energy Transfers

The Food Chain— Energy Transfers Between Living Things

The transfer of energy from one organism to another is called

a food chain. Food chains show how energy is passed from

one organism to another. The arrows between the organisms

show the direction of energy flow. The plant is eaten by the

mouse; the mouse is eaten by the snake; the snake is eaten by

the hawk.

An example of a food chain.

Frequently Asked Questions

Does Energy Change When It Is Transferred?

• Sometimes energy changes form when it is transferred.

For example, when sunlight falls on green plants, energy

is transferred from light to chemical energy.

• Other times energy moves but does not change form.

When a spoon is placed in a bowl of soup, heat energy is

transferred up the spoon handle without changing form.

Page 115: Solar Energy Field Trip

Chapter ���

How Can I Tell That Energy Is Being Transferred in the Natural World?

Easy, wherever you find change, energy is being transferred!

Seasons Change

The Earth Changes

Living Things Change

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��Recognizing Energy Transfers

How Can I Tell That Energy Is Being Transferred in the Natural World?

Easy, wherever you find change, energy is being transferred!

Seasons Change

The Earth Changes

Living Things Change

Page 117: Solar Energy Field Trip

���

A Walk Through Energy History

Energy has been making things happen since the dawn of

time. Take a walk through time and see how energy has been

used to change our world.

Not all the dates listed in this timeline are exact. Dates that are

approximations will have a “c.” in front of them. The “c.” stands

for “circa” meaning “around” and lets you know that the event

happened around that time.

A

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Appendix A��0

4.5 billion years ago Our sun begins shining, warming Earth with solar energy.

3.4 billion years ago Blue-green algae appear on Earth. They are the first plants—

organisms that convert the sun’s energy to food for growth.

1 million years ago Early humans (Homo erectus) use fire for warmth, protection,

and food preparation. Learning how to control fire was one of

the first great energy inventions.

c. 9000 b.c.Humans invent the bow and arrow, harnessing the elastic

energy of a bow to send arrows flying.

c. 3500 b.c.People put animals to use pulling wheeled vehicles in

Mesopotamia (present-day Iraq).

People use solar energy to dry out their crops and collect salt

(which is made by evaporating salt water).

c. 3200 b.c.Early drawings show Egyptian sailboats with a mast and a

single square sail hung from it. Oars are needed when not

traveling in the direction of the wind.

c. 3000 b.c.Humans begin using petroleum (oil from the earth). In

Mesopotamia, rock oil is used in medicines and in the glue

that holds ships and buildings together.

c. 1500 b.c.Polynesian canoes—canoes made of two hulls connected by

crossbeams—carry explorers over the vast waters of the Pacific

Ocean where they establish “new lives” on the Polynesian

Islands.

c. 285 b.c.A lighthouse is built at Alexandria in Egypt. The light from a

fire is reflected off a mirror and can be seen 30 miles away.

c. 200 b.c.Windmills are used to grind grain in Persia (present-day Iran)

and other countries in the Middle East.

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���A Walk Through Energy History

4.5 billion years ago Our sun begins shining, warming Earth with solar energy.

3.4 billion years ago Blue-green algae appear on Earth. They are the first plants—

organisms that convert the sun’s energy to food for growth.

1 million years ago Early humans (Homo erectus) use fire for warmth, protection,

and food preparation. Learning how to control fire was one of

the first great energy inventions.

c. 9000 b.c.Humans invent the bow and arrow, harnessing the elastic

energy of a bow to send arrows flying.

c. 3500 b.c.People put animals to use pulling wheeled vehicles in

Mesopotamia (present-day Iraq).

People use solar energy to dry out their crops and collect salt

(which is made by evaporating salt water).

c. 3200 b.c.Early drawings show Egyptian sailboats with a mast and a

single square sail hung from it. Oars are needed when not

traveling in the direction of the wind.

c. 3000 b.c.Humans begin using petroleum (oil from the earth). In

Mesopotamia, rock oil is used in medicines and in the glue

that holds ships and buildings together.

c. 1500 b.c.Polynesian canoes—canoes made of two hulls connected by

crossbeams—carry explorers over the vast waters of the Pacific

Ocean where they establish “new lives” on the Polynesian

Islands.

c. 285 b.c.A lighthouse is built at Alexandria in Egypt. The light from a

fire is reflected off a mirror and can be seen 30 miles away.

c. 200 b.c.Windmills are used to grind grain in Persia (present-day Iran)

and other countries in the Middle East.

Page 120: Solar Energy Field Trip

Appendix A���

c. 100 b.c. Waterwheels are used in what is now central Turkey.

One-wheeled carts (wheelbarrows) are invented in China.

a.d. 79 Mt. Vesuvius erupts in Italy and buries the towns of

Herculaneum and Pompeii.

c. a.d. 800 Vikings use longboats—boats with long hulls (longer hulls

provide more room for oars and rowers than short hulls)—to

carry warriors and weapons swiftly over the waters of the North

Atlantic and northern Europe. The Vikings invade Northern

Europe for hundreds of years with the help of these ships.

c. a.d. 1000 Natural gas wells are drilled in China. The gas flows through

bamboo tubes (the first known “pipelines”), possibly providing

the heat needed to make porcelain.

a.d. 1044A man named Wu Ching Tsao Yao of China writes the first

known recipe for making saltpeter, the main ingredient in the

gunpowder still used in today’s fireworks.

a.d. 1201The deadliest earthquake in history, which killed 1.1 million

people, strikes Egypt and Syria.

c. 1470–1510Leonardo da Vinci, an Italian artist and inventor, sketches

plans for inventions hundreds of years before they are actually

made. They include a bicycle, a flying machine, a helicopter, a

propeller, and a parachute.

c. 1600–1700Despite its smoke and fumes, coal replaces wood as the most

common way of heating homes in Europe.

1610Galileo Galilei describes the motion of the planets around

the sun.

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���A Walk Through Energy History

c. 100 b.c. Waterwheels are used in what is now central Turkey.

One-wheeled carts (wheelbarrows) are invented in China.

a.d. 79 Mt. Vesuvius erupts in Italy and buries the towns of

Herculaneum and Pompeii.

c. a.d. 800 Vikings use longboats—boats with long hulls (longer hulls

provide more room for oars and rowers than short hulls)—to

carry warriors and weapons swiftly over the waters of the North

Atlantic and northern Europe. The Vikings invade Northern

Europe for hundreds of years with the help of these ships.

c. a.d. 1000 Natural gas wells are drilled in China. The gas flows through

bamboo tubes (the first known “pipelines”), possibly providing

the heat needed to make porcelain.

a.d. 1044A man named Wu Ching Tsao Yao of China writes the first

known recipe for making saltpeter, the main ingredient in the

gunpowder still used in today’s fireworks.

a.d. 1201The deadliest earthquake in history, which killed 1.1 million

people, strikes Egypt and Syria.

c. 1470–1510Leonardo da Vinci, an Italian artist and inventor, sketches

plans for inventions hundreds of years before they are actually

made. They include a bicycle, a flying machine, a helicopter, a

propeller, and a parachute.

c. 1600–1700Despite its smoke and fumes, coal replaces wood as the most

common way of heating homes in Europe.

1610Galileo Galilei describes the motion of the planets around

the sun.

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Appendix A���

1687 Isaac Newton publishes the Principia—thought to be one of the

greatest scientific books of all time—in which he presents his

theory of gravitation (every particle of matter attracts every other

particle). He also publishes his three Laws of Motion—laws that

describe and predict the motion of all objects on Earth. Newton

also wrote about the behavior of light, including how it can be

divided into colors by a glass prism.

1690 The clarinet, one example of sound energy being used to make

music, was invented in Germany.

1714 The mercury thermometer is introduced by Gabriel Fahrenheit.

Earlier thermometers, which used air instead of mercury, were

not as dependable since they were affected by atmospheric

changes. Atmospheric changes had no effect on the mercury

used to indicate temperature in Fahrenheit’s thermometer.

c. 1750Benjamin Franklin figures out that lightening is actually static

electricity. He also invents a very efficient stove for heating homes.

1769James Watt patents the first efficient steam engine.

1781The stagecoach carries passengers from place to place

throughout the world.

1787On the Delaware River, John Fitch makes the first successful

steamboat voyage.

1800sThe first iceboxes (the earliest “refrigerators”) are used in

homes. They are wooden boxes lined with tin or zinc and

insulated with materials such as cork, sawdust, and seaweed.

These early iceboxes are used to hold blocks of ice and “refrig-

erate” food. A drip pan underneath, which collects melted ice

water, has to be emptied daily.

1801Allesandro Volta creates the first electric battery.

Page 123: Solar Energy Field Trip

���A Walk Through Energy History

1687 Isaac Newton publishes the Principia—thought to be one of the

greatest scientific books of all time—in which he presents his

theory of gravitation (every particle of matter attracts every other

particle). He also publishes his three Laws of Motion—laws that

describe and predict the motion of all objects on Earth. Newton

also wrote about the behavior of light, including how it can be

divided into colors by a glass prism.

1690 The clarinet, one example of sound energy being used to make

music, was invented in Germany.

1714 The mercury thermometer is introduced by Gabriel Fahrenheit.

Earlier thermometers, which used air instead of mercury, were

not as dependable since they were affected by atmospheric

changes. Atmospheric changes had no effect on the mercury

used to indicate temperature in Fahrenheit’s thermometer.

c. 1750Benjamin Franklin figures out that lightening is actually static

electricity. He also invents a very efficient stove for heating homes.

1769James Watt patents the first efficient steam engine.

1781The stagecoach carries passengers from place to place

throughout the world.

1787On the Delaware River, John Fitch makes the first successful

steamboat voyage.

1800sThe first iceboxes (the earliest “refrigerators”) are used in

homes. They are wooden boxes lined with tin or zinc and

insulated with materials such as cork, sawdust, and seaweed.

These early iceboxes are used to hold blocks of ice and “refrig-

erate” food. A drip pan underneath, which collects melted ice

water, has to be emptied daily.

1801Allesandro Volta creates the first electric battery.

Page 124: Solar Energy Field Trip

Appendix A���

1821 Michael Faraday demonstrates that a moving magnet causes

electricity to flow through wires. This paves the way for the

electric motor and generator to be invented.

1827 The first photographic picture was produced by a French man

named Nicephore Niepce. He put a metal plate coated with

a special chemical into a camera box and took a picture—

exposing the plate to the sun’s energy (this took eight hours!).

When he washed it off he discovered that a permanent picture

remained.

English chemist John Walker invents the wooden match.

1830The first regular steam train passenger service starts.

1836In America, Samuel F. B. Morse sends messages over wires with

the first telegraph.

1843James Prescott Joule conducts a series of experiments to dem-

onstrate the law of conservation of energy: energy can neither

be created out of nothing nor destroyed into nothing, but

can be changed from one form to another.

Page 125: Solar Energy Field Trip

���A Walk Through Energy History

1821 Michael Faraday demonstrates that a moving magnet causes

electricity to flow through wires. This paves the way for the

electric motor and generator to be invented.

1827 The first photographic picture was produced by a French man

named Nicephore Niepce. He put a metal plate coated with

a special chemical into a camera box and took a picture—

exposing the plate to the sun’s energy (this took eight hours!).

When he washed it off he discovered that a permanent picture

remained.

English chemist John Walker invents the wooden match.

1830The first regular steam train passenger service starts.

1836In America, Samuel F. B. Morse sends messages over wires with

the first telegraph.

1843James Prescott Joule conducts a series of experiments to dem-

onstrate the law of conservation of energy: energy can neither

be created out of nothing nor destroyed into nothing, but

can be changed from one form to another.

Page 126: Solar Energy Field Trip

Appendix A���

1845 The rubber band is patented by Stephen Perry of London.

1859 Edwin L. Drake strikes oil at his homemade drilling rig in Titus-

ville, Pennsylvania. This is the first oil well in the United States.

It marks the beginning of the modern oil industry, which now

fuels the transportation and energy needs of the world.

1860s The booming steel industry greatly increases the demand

for coal.

1863 In the city of London, the first subway is built.

1865 James Clark Maxwell presents his electromagnetic theory,

which other inventors use to invent electric power, radios,

and television.

1876 Alexander Graham Bell invents the telephone.

1877 Thomas Edison invents the phonograph.

1879Thomas Edison patents an incandescent light bulb.

1880Wabash, Indiana becomes the first town completely illumi-

nated by electric lighting.

1882The world’s first hydroelectric plant opens in Appleton,

Wisconsin, demonstrating that moving water can generate

electricity.

1884The “Rover” bicycle, the first to have all the major features of

today’s bicycles, is introduced in Great Britain.

The first long-distance telephone call is made between Boston

and New York City.

1885Gottlieb Daimler and Karl Benz of Germany invent gasoline

engines similar to those still used in cars today.

1895Wilhelm Roentgen x-rays his wife’s hand to produce the first

“x-ray picture.”

Guglielmo Marconi sends and receives the first radio signal,

which leads to the invention of the radio.

Page 127: Solar Energy Field Trip

���A Walk Through Energy History

1845 The rubber band is patented by Stephen Perry of London.

1859 Edwin L. Drake strikes oil at his homemade drilling rig in Titus-

ville, Pennsylvania. This is the first oil well in the United States.

It marks the beginning of the modern oil industry, which now

fuels the transportation and energy needs of the world.

1860s The booming steel industry greatly increases the demand

for coal.

1863 In the city of London, the first subway is built.

1865 James Clark Maxwell presents his electromagnetic theory,

which other inventors use to invent electric power, radios,

and television.

1876 Alexander Graham Bell invents the telephone.

1877 Thomas Edison invents the phonograph.

1879Thomas Edison patents an incandescent light bulb.

1880Wabash, Indiana becomes the first town completely illumi-

nated by electric lighting.

1882The world’s first hydroelectric plant opens in Appleton,

Wisconsin, demonstrating that moving water can generate

electricity.

1884The “Rover” bicycle, the first to have all the major features of

today’s bicycles, is introduced in Great Britain.

The first long-distance telephone call is made between Boston

and New York City.

1885Gottlieb Daimler and Karl Benz of Germany invent gasoline

engines similar to those still used in cars today.

1895Wilhelm Roentgen x-rays his wife’s hand to produce the first

“x-ray picture.”

Guglielmo Marconi sends and receives the first radio signal,

which leads to the invention of the radio.

Page 128: Solar Energy Field Trip

Appendix A��0

1902 Willis Carrier builds the first air conditioner.

1903 The Wright Brothers fly the first engine-powered airplane near

Kitty Hawk, North Carolina. Their machine flies for 59 seconds,

and reaches an altitude (height) of 852 feet.

1905 Einstein links mass with energy through his famous formula

E=mc2.

This theory eventually led to nuclear power, nuclear weapons,

nuclear medicine, and the field of astrophysics.

The first “portable” electric vacuum cleaner is produced. It

weighs 92 pounds!

The first electric washing machine is sold.

1910Thomas Edison demonstrates “talking” pictures—the first

movies with sound “blended” in.

The first flight powered by a jet engine takes place over Paris,

France.

1911Marie Curie wins the Nobel Prize in Chemistry for her work

isolating radium, a substance which gives off radioactive

energy. Years later, radium is used to treat cancer.

1913The first “non-icebox” refrigerators (made with compressors)

for home use are manufactured in Chicago.

Page 129: Solar Energy Field Trip

���A Walk Through Energy History

1902 Willis Carrier builds the first air conditioner.

1903 The Wright Brothers fly the first engine-powered airplane near

Kitty Hawk, North Carolina. Their machine flies for 59 seconds,

and reaches an altitude (height) of 852 feet.

1905 Einstein links mass with energy through his famous formula

E=mc2.

This theory eventually led to nuclear power, nuclear weapons,

nuclear medicine, and the field of astrophysics.

The first “portable” electric vacuum cleaner is produced. It

weighs 92 pounds!

The first electric washing machine is sold.

1910Thomas Edison demonstrates “talking” pictures—the first

movies with sound “blended” in.

The first flight powered by a jet engine takes place over Paris,

France.

1911Marie Curie wins the Nobel Prize in Chemistry for her work

isolating radium, a substance which gives off radioactive

energy. Years later, radium is used to treat cancer.

1913The first “non-icebox” refrigerators (made with compressors)

for home use are manufactured in Chicago.

Page 130: Solar Energy Field Trip

Appendix A���

Henry Ford thinks of a way for workers to use a conveyor belt

to speed up production of the Model T Ford. Soon most manu-

facturers use this method to make large quantities of their

products, including cars.

1919 The modern pop-up toaster, which uses a timer to toast bread

to the desired doneness, is introduced by Charles Strite.

1926 First liquid-fuel rocket is launched by Robert Goddard.

1927 Philo T. Farnsworth successfully transmits a television signal.

The picture on the television screen is black and white.

1935 Major league baseball games are played at night for the first

time. Night games are made possible by electric lighting.

1936 The Hoover (Boulder) Dam is completed.

1938 The first color television is demonstrated in London.

1940A helicopter is invented by Igor Sikorsky—more than 400 years

after Leonardo da Vinci first describes this invention.

1942Scientists demonstrate the first controlled production of

nuclear energy.

1945The first atomic bomb is tested.

1947The microwave oven, invented by Percy Spencer, is introduced

by Raytheon Corporation.

1952The United States explodes the first hydrogen bomb.

1954Scientists show that the sun’s energy can be converted to elec-

tric current using silicon solar collectors.

The United States launches the USS Nautilus—the world’s first

nuclear-powered submarine.

1957The first commercial nuclear power plant begins operating in

Shippingport, Pennsylvania.

Page 131: Solar Energy Field Trip

���A Walk Through Energy History

Henry Ford thinks of a way for workers to use a conveyor belt

to speed up production of the Model T Ford. Soon most manu-

facturers use this method to make large quantities of their

products, including cars.

1919 The modern pop-up toaster, which uses a timer to toast bread

to the desired doneness, is introduced by Charles Strite.

1926 First liquid-fuel rocket is launched by Robert Goddard.

1927 Philo T. Farnsworth successfully transmits a television signal.

The picture on the television screen is black and white.

1935 Major league baseball games are played at night for the first

time. Night games are made possible by electric lighting.

1936 The Hoover (Boulder) Dam is completed.

1938 The first color television is demonstrated in London.

1940A helicopter is invented by Igor Sikorsky—more than 400 years

after Leonardo da Vinci first describes this invention.

1942Scientists demonstrate the first controlled production of

nuclear energy.

1945The first atomic bomb is tested.

1947The microwave oven, invented by Percy Spencer, is introduced

by Raytheon Corporation.

1952The United States explodes the first hydrogen bomb.

1954Scientists show that the sun’s energy can be converted to elec-

tric current using silicon solar collectors.

The United States launches the USS Nautilus—the world’s first

nuclear-powered submarine.

1957The first commercial nuclear power plant begins operating in

Shippingport, Pennsylvania.

Page 132: Solar Energy Field Trip

Appendix A���

1958 Scientists at AT&T Bell Laboratories invent the laser.

1963 The Clean Air Act is passed to protect Americans from harmful

air pollutants, such as those released by coal power plants and

steel mills.

1966 The first hand-held pocket calculator is invented.

1974 University City, Missouri is the first city to pick up recycling

from homes (newspapers only).

1976Edward Hammer presents an idea for a fluorescent “spiral

lamp.” Because of its high cost, compact fluorescent light

bulbs do not appear in stores until 1995.

1977The first cell phones are tried out in Chicago by two thousand

customers.

1978Texas Instruments patents the microchip for use in computers.

1980sThe first wind farms are built in the United States, providing

an alternative to power plants that burn fossil fuels.

Page 133: Solar Energy Field Trip

���A Walk Through Energy History

1958 Scientists at AT&T Bell Laboratories invent the laser.

1963 The Clean Air Act is passed to protect Americans from harmful

air pollutants, such as those released by coal power plants and

steel mills.

1966 The first hand-held pocket calculator is invented.

1974 University City, Missouri is the first city to pick up recycling

from homes (newspapers only).

1976Edward Hammer presents an idea for a fluorescent “spiral

lamp.” Because of its high cost, compact fluorescent light

bulbs do not appear in stores until 1995.

1977The first cell phones are tried out in Chicago by two thousand

customers.

1978Texas Instruments patents the microchip for use in computers.

1980sThe first wind farms are built in the United States, providing

an alternative to power plants that burn fossil fuels.

Page 134: Solar Energy Field Trip

Appendix A���

1982 The compact disc is available in stores.

1984 The first modern tidal power plant in North America opens

in Nova Scotia, demonstrating that the motion energy of the

tides can be used to generate electricity.

2004 Hybrid electric cars become widely available at car dealerships.