September 13, 2010

Agenda Types of Energy Introduction of Unit

Project

Homework Identify and

describe 5 different renewable energy sources used to produce power to our homes

BrainTeaser Fossil fuels (coal,

oil and gas) will eventually run out. Why are they called “fossil” fuels?

Why are they so important to our society?

Unit 3 Objectives

Understand how energy is stored in a system

Describe how energy is transferred from one system to another

Energy is conserved in a closed system

Energy: Energy: Forms and Forms and ChangesChanges

Nature of Energy

Energy is all around you!You can hear energy as sound.You can see energy as light.And you can feel it as wind.

Nature of Energy

You use energy when you: hit a softball. lift your book

bag. compress a

spring.

Nature of Energy

Living organisms need energy for growth and

movement.

Nature of Energy

Energy is involved when: a bird flies. a bomb explodes. rain falls from the

sky. rollercoasters rise

and fall electricity flows in

a wire.

A burning match releases energy.

Source: ElektraVision/PictureQuest

The sun is the source of all energy we use

Nature of Energy

What is energy that it can be involved in so many different activities?

Energy Expert Jigsaw

Begin by summarizing the information in the article that your group was assigned

Then form groups of 3—1 representative from each article group

List Energy types and sources

Use the notes that you made from your article group.

Make a list of at least 30 words of energy types and sources in your 3 person group

examples

Nuclear chemical gasoline electricity batteries fusion oil Mechanical kinetic potential natural gas Steam food light microwaves hydro Fission thermal sound x-rays heat Uranium

wind tides hot water gun powder wound up spring toy static cling ball in motion heavy water hydro solar ultraviolet rays turning drill bit lightning wood stretched bungee cord star light heat lamp stretched rubber band charcoal heavy water compass

CHEMISTRY

September 15, 2010

Warm Up

Name 5 sources of renewable energy.

September 14, 2010

Agenda Warm Up Collect Unit 2 Review: Period 5 Unit 3:

The Law of Conservation of Energy Energy Conversions

Information on Research ProjectHomeworkEnergy Jigsaw HomeworkBegin ProjectResearch

What IS energy?

Energy (E): The ability to do work or produce heat (units of Joules or KiloWatt hour)

Work (w): The capacity to move an object over a distance against a resisting force (units of Joules or Newton-meters)

What IS energy?

Because of the direct connection between energy and work, energy is measured in the same unit as work: joules (J).

In addition to using energy to do work, objects gain energy because work is being done on them.

What about POWER?

Power: the rate at which work can be done, i.e. a measure of how quickly work can be done (units of Watts)

Power is like the strength of a weightlifter, energy is like his endurance. The work the weightlifter does is moving the weights from the ground to over his head.

Can you think of other examples?

States of Energy

All forms of energy can be in either of two states: Potential Kinetic

Potential Energy

Energy due to the composition or the position of an object

Composition: type of atoms, number and types of chemical bonds and arrangement of the atoms

Position: objects waiting to fall off a shelf

Potential Energy

Potential Energy is stored energy. Stored chemically in fuel, the nucleus of

atom, and in foods. Or stored because of the work done on

it: Stretching a rubber band. Winding a watch. Pulling back on a bow’s arrow. Lifting a brick high in the air.

Potential Energy

Energy that is stored due to being stretched or compressed is called elastic potential energy.

Gravitational Potential Energy

Potential energy that is dependent on height is called gravitational potential energy.

Gravitational Potential Energy

A waterfall, a suspension bridge, and a falling snowflake all have gravitational potential energy.

Gravitational Potential Energy

“The bigger they are the harder they fall” is not just a saying. It’s true. Objects with more mass have greater G.P.E.

The formula to find G.P.E. isG.P.E. = Weight X Height.

Kinetic Energy

Kinetic Energy of motion

moving objects, moving particles, vibrating molecules, etc

Kinetic Energy

The faster an object moves, the more kinetic energy it has.

The greater the mass of a moving object, the more kinetic energy it has.

Kinetic energy depends on both mass and velocity.

Forms of Energy

The six main forms of energy are:ElectricHeatChemicalElectromagnetic (light)NuclearMechanicalOther (gravitational, spring, magnetic)

Energy Jigsaw Assignment

Group any types, sources, or associated words that seem to refer to the same type of energy.

You can do this using colored pencils, or by making lists of each set of words that seem to be a given type of energy.

Try to get all of the words into 7 categories, one for each basic type of energy.

Electrical (PE)

flow of mobile electrons

A bolt of lightning contains enough energy to toast 160,000 pieces of bread. Unfortunately the bolt only takes 1/10,000 of a second – so turning the bread over might prove difficult.

Heat / Thermal Energy (KE)

The internal motion of the atoms is called heat energy, because moving particles produce heat

Heat energy can be produced by friction.

Heat energy causes changes in temperature and phase of any form of matter.

heat as energy

Chemical Energy (PE)

Chemical Energy is required to bond atoms together.

And when bonds are broken, energy is released.

Chemical Energy

Fuel and food are forms of stored chemical energy.

One kilogram of butter stores as much energy between its atoms as the same quantity of TNT.

Frequencies of radiation in the electromagnetic spectrum—waves are always in motion

Electromagnetic Energy (KE)

Light is a form of electromagnetic energy.

Each color of light (Roy G Bv) represents a different amount of electromagnetic energy.

Electromagnetic Energy is also carried by X-rays, radio waves, and laser light.

Did you know?

If 10 kilograms of matter spontaneously turned into energy there would be enough energy to power a 100 Watt light bulb for 300 million years!!!

Nuclear Energy (PE)

The nucleus of an atom is the source of nuclear energy.

Nuclear Energy

When the nucleus splits (fission), nuclear energy is released in the form of heat energy and light energy.

Nuclear energy is also released when nuclei collide at high speeds and join (fusion).

Nuclear Energy

The sun’s energy is produced from a nuclear fusion reaction in which hydrogen nuclei fuse to form helium nuclei.

Nuclear Energy

Nuclear energy is the most concentrated form of energy.

The amount of sunlight reaching the earth's surface is 6,000 times the amount of energy used by all human beings worldwide. The total amount of fossil fuel used by humans since the start of civilization is equivalent to less than 30 days of sunshine.

Mechanical Energy (KE)

The motion of objects Kicking a football Throwing a bowling ball

Check 4 Understanding Energy of stars Energy of a substance changing

states (gas to liquid, liquid to solid, etc)

Energy of batteries Energy of tanning lamps

Clicking of a computer mouse

Energy of lightning

Nuclear fusion

Heat

Chemical Light

(ultraviolet)

Mechanical

Electrical

Warm Up

Classify these forms of energy as Kinetic or Potential energyElectricHeatChemicalElectromagnetic (light)NuclearMechanical

September 14, 2010

Agenda The Law of

Conservation of Energy

Energy Conversions

HomeworkBegin Research Unit 3 Worksheet 1

Law of Conservation of Energy

Energy cannot be created or destroyed but it can change its form.

Compound Machines

Energy IN = Energy OUTEnergy released = Energy absorbedEnergy of a system = Energy of

surroundings

The Law of Conservation of Energy

Energy can be neither created nor destroyed by ordinary means. It can only be converted from one form

to another. If energy seems to disappear, then

scientists look for it – leading to many important discoveries.

System: whatever we’re studying

Surroundings: everything outside the system

Universe = system + surroundings

• If we’re studying a space heater, the heater will be our system, the house will be our surroundings, and the universe will be the heater and the house together (we ignore the irrelevant rest of the world, since it doesn’t really play a part in anything).

Energy Conversion

Energy can be changed from one form to another. Changes in the form of energy are called energy conversions.

Energy conversions

All forms of energy can be converted into other forms. The sun’s energy through solar cells

can be converted directly into electricity.

Green plants convert the sun’s energy (electromagnetic) into starches and sugars (chemical energy).

Other energy conversions

In an electric motor, electric energy is converted to mechanical energy.

In a battery, chemical energy is converted into electromagnetic energy.

The mechanical energy of a waterfall is converted to electrical energy in a generator.

Examples

You can use the energy of moving turbines (kinetic) to charge a battery (potential)

You can take the stored gravitational energy of a book on a shelf and make it into the kinetic energy of the book moving through the air.

Some people who have two or more different kinds of fillings in their teeth are able to hear high-power AM broadcast stations when located within a few hundred feet of the stations. In such cases, the strong radio waves act upon the teeth fillings in such a way that the electromagnetic oscillations get transformed to mechanical vibrations in the person's head, and these are heard as sound.

Energy Trace

The objective is to illustrate how energy is essential in our daily lives by tracing back to where energy starts.

First, identify a sequence of events. Second, identify the type of energy

that is involved. Third, identify the source of the

energy.

Waking up in the morning

Event Type of Energy Source

Alarm clock wakes me up Electrical/Sound Power Company

Power company distributes electricity Mechanical Water

Snow melts to make water Thermal Sun

Energy Conversions

In an automobile engine, fuel is burned to convert chemical energy into heat energy. The heat energy is then changed into mechanical energy.

Chemical Heat Mechanical

Kinetic-Potential Energy Conversion

Roller coasters work because of the energy that is built into the system. Initially, the cars are pulled mechanically up the tallest hill, giving them a great deal of potential energy. From that point, the conversion between potential and kinetic energy powers the cars throughout the entire ride.

Kinetic vs. Potential Energy

At the point of maximum potential energy, the car has minimum kinetic energy.

Kinetic-Potential Energy Conversions

As a basketball player throws the ball into the air, various energy conversions take place.

Ball slows down Ball speeds up

Energy Research Project

You will work in groups of 3 Pick your partners carefully

Pick them for reliability and their strengths in the following areas:

Designing a powerpoint Research and summarizing information cost benefit analysis (looking at all sides

of an issue and being objective) Working with a team

Arizona Corporation Commission Utilities

SRP Salt River Project APS Arizona Public Service TEP Tuscon Electric Power AIC Ajo Improvement Company NEC Navopache Electric

Cooperative MEC Mohave Electric Cooperative And more…..

The coal is burned in a boiler which produces steam. The steam is run through a turbine which turns a generator which produces electricity. A turbine is like a fan in reverse, with many vanes or blades, where the steam is used to make the turbine turn or rotate rapidly. A generator is a huge magnet that is turned by the turbine. As the magnet turns inside a coil of wire, electricity is produced. So, the energy chain for this power plant would look like this:Chemical Heat Mechanical Electrical

energy plant game

http://www.fi.edu/guide/hughes/discussiontopics.html

Vocabulary Wordsenergymechanical energyheat energychemical energyelectromagnetic energynuclear energykinetic energypotential energygravitational potential energyenergy conversionLaw of Conservation of Energy

The second law of thermodynamics is a general principle which places constraints upon the direction of heat transfer and the attainable efficiencies of heat engines.

Spontaneous processes always proceed in such a way that the entropy of the universe increases.

Entropy is a measure of disorder or randomness of the particles that make up a system.

Energy Efficiency

No system is 100% efficient With Energy, we look at the ratio of the

useful energy gotten out to the energy put in

Generally, wasted energy is observed as heat.

When researching your energy technologies, be aware of the engines and mechanical machines which will lower your efficiencies.

there has to be an energy transfer for something to happen; energy changes form or moves from place to place

each time energy gets transferred or transformed, some of it, and eventually all of it, gets less useful

Video: Efficiency_of_Energy_Conversions