Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Bellwork
What do the following a plant, a Bunsen burner, and a
pendulum have in common? What are three other
objects that have same common link?
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Kinetic Energy and Potential Energy
• An energy conversion is a change from one form of
energy to another. Any form of energy can change into
any other form of energy.
• As the skateboarder on the next slide travels up and
down the half-pipe, his energy changes back and forth
between kinetic energy and potential energy.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Kinetic Energy and Potential Energy,
continued
• Elastic Potential Energy Stretching a rubber band
stores elastic potential energy in the rubber band.
• When you let the rubber band go, it goes back to its
original shape. It releases its stored-up potential
energy as it does so.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Conversions Involving Chemical Energy
• Chemical energy is stored in the food you eat. Your
body uses this chemical energy to function.
• Energy Conversion in Plants The chemical energy
in the food you eat comes from the sun’s energy.
Plants use photosynthesis to convert light energy into
chemical energy, as shown on the next slide.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Conversions Involving Chemical Energy,
continued
• The Process Continues Plants change light energy
into chemical energy. The chemical energy in the food
you eat is changed into another kind of chemical
energy that your body can use.
• Your body then uses that energy to give you kinetic
energy that you use in everything you do.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Why Energy Conversions Are Important
• Energy conversions are needed for everything we do.
Heating our homes, getting energy from a meal, and
many other things use energy conversions.
• Machines, such as a hair dryer, help harness energy
and make that energy work for you.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Why Energy Conversions Are Important,
continued
• Conversions Involving Electrical Energy Some
common energy conversions that involve electrical
energy are shown in the table below.
Chapter 5
Alarm clock electrical energy light and sound energy
Battery chemical energy electrical energy
Light bulb electrical energy light and thermal energy
Blender electrical energy kinetic and sound energy
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions
Energy and Machines
• A machine can make work easier by changing the
size or direction (or both) of the force needed to do the
work. Some machines allow you to use less force over
a greater distance to do the same amount of work.
• Machines as Energy Converters Some machines
help you use energy by converting it into the form of
energy that you need.
Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 2 Energy Conversions Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 3 Conservation of Energy Chapter 5
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resources Chapter menu
Section 4 Energy Resources Chapter 5