1. Does Energy (Light) Have Either Weight Or Volume? 8

Energy

A. What Is Energy?

1. Does Energy (Light) Have Either Weight Or Volume? ------8

2. What Makes It Move? ------9

2. Defining Energy? ------10

3. How Is Energy / Work Measured? ------12

4. How Is the Strength Energy Measured? (The Inverse Square Law) ------13

B. Forms of Energy.

1. The Seven Forms Of Energy------16

2. Energy and the Human Body ------18

3. Transfer Of Chemical To Heat - Food Burning ------23

4. Can Heat Make Things Move? ------24

5. Can Chemicals Make Things Move?------26

6. Using A Radio Speaker to Send Your Voice------29

7. Changing Mechanical Energy To Heat Energy ------31

8. Energy Conversion Smorgasbord------32

9. Energy Conversion Summary ------36

10. Energy Chains ------38

C. Types of Energy.

1. Two types of Energy-Potential and Kinetic ------40

2. Ah-La-Bounce ------41

3. The weight of A Body and Its Gravitational Potential Energy------44

4. Galilean Cannon ------46

5. Another Way Of Storing Energy ------47

6. Investigating Potential / Kinetic Energy ------52

a. Does Potential / Kinetic Energy depend on Force?

b. Does Potential / Kinetic Energy depend on Mass?

D. Conservation of Energy (Energy cannot be Created Nor Destroyed “In Ordinary Circumstances”)

1. Is Energy Conserved When Converted to Work? ------57

a. Is Energy Conserved When Force is Changed?

b. Is Energy Conserved When Mass is Changed?

2. Energy Transformations and The Pendulum ------59

3. Stop And Go Balls ------60

4. Coat Hanger Cannon ------63

5. Energy Transformations And The Hand Generator ------64

E. Work and Power

1. Determining Your Horsepower?------70

2. Hot Rod Power------72

F. Energy Conversion Game------73

WORKSHOP LEADER TOPIC INFORMATION
INTRODUCTION TO ENERGY

Energy is divided into four subtopics:

What is Energy?
Forms of energy and conversions
Types of Energy - Kinetic and Potential Energy.
Conservation of Energy.

The first subtopic examines the meaning of the term "energy," noting that energy is not a "thing," but rather a property that objects can have. It begins with the idea that energy can make something move. The difference between force and energy is discussed, work is defined and a more complete definition of energy as, "the ability to do work" is developed. These concepts are reinforced by examining the energy input and output of the human body.

The second subtopic concerns some of the many forms of energy. In both demonstrations and lab activities, the students are given many opportunities to reinforce the notion that energy is the ability to do work, that energy can be measured, and that one form of energy can be transformed into another form of energy.

The third subtopic concerns potential energy and kinetic energy. Through a variety of activities the factors that affect these kinds of energy are discovered, and for the upper levels the equations of gravitational potential energy and kinetic energy are introduced

The last subtopic explores the concept of energy conservation. Through activities, demonstrations, and discussion, the participants examine the idea that although energy can be transformed the total amount of energy remains the same. The concept of why we could run out of energy even though it is conserved is also addressed. This is followed by a discussion of mass-energy conservation, which is intended as an enrichment topic that can be presented with varying degrees of depth.

While the scope of this book is limited to the 'physics" of energy (which is often not discussed in many other popular materials), it is recognized that the topic has many environmental, economic and social implications. The amount and the forms of energy that we use are now seen to have a direct relationship to how we live our lives. The bibliography contains a sample of some of the many resources that address these issues. Teachers are encouraged to use an interdisciplinary approach to this topic to help their students reach an understanding of the relationship between energy and society.

WORKSHOP PLANNING MATRIX.- FNERGY

Name of

IdeaActivityTypeLevelDuration

I. What is Energy?

Energy can make1. What Makes itLabLA)20-25 min.

things move.Move?

Energy is the ability1. Focus on PhysicsDisc.T30 min.

to do work.Defining Energy

How is WorkLabL/U30-45 min. Measured?
How Much EnergyLabL/U20-30 min. Do You Use in Climbing a Flight of Stairs?
Energy and theLabL/U20-30 min. class time

Human Body24 hr. total time

II. There Are Many Forms of Energy,

Some forms of1. Some FormsDemoL/U30 min.

energy are: heat,of Energy

light (radiant),

sound, mechanical2. Can Heat EnergyLabL/U15 min.

electrical and chemical.Make Things Move?

. 3. Can ChemicalsLabL25-30 min.

Make Things

Move?

Energy can be1. Energy ChainsLabL/U20 min. changed from

transformed 2. EnergyLabL/U15-20 min.

from one form Transformations

to another. 3. DemonstratingLabL/U30-40 min. Energy Transformations

When energy is1. Can you ChangeDemo/ T20 min.

changed fromMechanicalDisc.

one form toEnergy to Heat

another, oftenEnergy?

some energy is

changed to2. Can youLabL/U25 min.

heat energy.Change

Mechanical

Energy (motion)

to Heat Energy?

3. Heat EnergyLabL/U45 min. Smorgasbord

III. Kinetic and Potential Energy,

A body may have1. Focus On Physics:DemoT25 min.

energy by virtuePotential EnergyDisc.

of its position or

condition. This2. How Do Weight andLabL/U25-30 min.

type of energy isHeight Affect

called potentialGravitational Potential

or "stored up" energy.Energy?

3. Another Way ofLabL/U30-45 min. Storing Energy

A body may have1. Focus On Physics:Disc.T30 min.

energy by virtue ofKinetic Energy

its motion. This type

of energy is called. 2. Do Speed and MassLabL30-40 min.

kinetic energy.Affect Kinetic Energy?

IV. Conservation of Energy

A. Energy can only1. Energy -LabL/U30 min.

be transformed, the.Transformations

total amount of

energy remains the2. Stop and Go BallsDemo. L/U15 min.

same.Disc.

EnergyLabL/U30 min. dons and the Hand

Transformation

Generator

What is Energy?Disc.T15 min.

Even though the1. If the Amount oflabL/U 30 min.

total amount of Energy in the Universe

energy in the universe is Constant, Why Must

is constant, it is not We Conserve It?

always in a useful form

In special1. Focus onDisc.T 20 Min.

situations, Like Physics:

nuclear reactions, E=mc2

energy can be converted
to matter, and
matter into energy.

REFERENCES AND RESOURCES

Anderson, F.J. and Freier, G. D., A Demonstration Handbook for Physics, Stony Brook, N. Y.: American Association of Physics Teachers. Second Makin

This publication has a wealth of simple demonstrations from all areas of physics and many that relate to the topic of energy.

Enterprise for Education. Energy 80's, Santa Monica, CA: Enterprise for Education.

Check with your local utility company for this excellent collection of books loaded with ideas and demonstrations in energy education. If the set is not available in your area. write to Enterprise of Education, 1320A Santa Monica Mall, Suite 203, Santa Monica, CA 90401.

Hewitt, Paul. Conceptual Physics. Boston, Mass.: Little, Brown and Company, 5th Edition.

The chapter on energy and the section on heat are good background reading for the workshop presenters. Note in particular, the home projects and exercises for these sections.

Lem, Tick L., Invitations to Science Inquiry. Lexington, Mass.: Ginn Press.

This. book should be in the library of all general science teachers. Many activities and demonstrations are applicable to the topic of energy.

Oak Ridge Associated Universities. Science Activities in Energy, Oak Ridge Associated Universities, assisted by Lawrence Hall of Science.

This is a series of pamphlets available through your local utility company. Illustrated cartoon style, each sheet of activities can be copied and supplied to the students. Highly recommended.

Wilson, Mitchell and the editors of Life, Energy, New York Time, Inc

Part of the Life Science Library, this is an excellent resource for the historical development of energy concepts. Very nicely illustrated and good background reading.

In addition to the references listed above, all of the many elementary-junior high science series produced by various publishers contain projects, activities and demonstrations that the presenter might want to look over to expand the offerings of the workshop.

WORKSHOP LEADER'S PLANNING GUIDE
WHAT IS ENERGY?

Idea A, "Energy can make things move" is a first look at the concept of energy. By investigating toys many questions are raised, such as the difference between energy and force. This introductory activity is also an excellent opportunity for the presenter to determine the students' initial level of understanding of the concept of energy.

Energy is defined in idea B, "Energy is the ability to do work." In this section some activities measuring work will be performed and the units of measure for work and energy are discussed. The metric units used are consistent with current elementary science programs. Activity "Energy and the Human Body" reinforces these concepts and demonstrates the relevancy of energy in everyday life.

The only prerequisite for this topic is an understanding of the metric units of force and distance.

Naive Ideas:

The terms "energy" and "force" are interchangeable.

From the non-scientific point of view, "work" is synonymous with "labor." It is hard to convince someone that more "work" is probably being done playing football for one hour than studying an hour for a quiz.

ENERGY IS THE ABILITY TO MAKF THINGS MOVE.

1. Activity: What Makes it Move?

This activity uses toys to begin to define energy and address the naive idea that "energy" and "force" are interchangeable

ENERGY IS THE ABILITY TO DO WORK.

Discussion - Focus On Physics: Defining Energy
Activity How is Work Measured? The pulling of an object up an incline is used to define work and energy.
Activity: How Much Energy do you use in Climbing a Flight of Stairs?

The energy used to climb a flight of stairs is calculated in order to illustrate the joule as the unit of work and energy.

Activity: Energy and the Human Body

An attempt to measure the energy input and output of a human body is made in order to show the relevancy of energy in everyday life.

DOES ENERGY HAVE WEIGHT OR TAKE UP SPACE?

Materials: Flashlight or desk lamp, Infant scale, bathroom scale, or lab balance. Measuring cup or graduated cylinder water, Radiometer

PART I: Does energy (light) have weight?

Record the reading on the scale.

Predict what will happen when you shine the flashlight on the scale.

3. Observe the scale very carefully as you shine the flashlight. record the weight.

Experiment by varying the distance of the light from the scale (do not let the flashlight touch the scale!) Try using a stronger source of light.

From your experiment, what can you conclude about energy having weight?

Can you think of any reasons why this experiment might not be a good method of determining whether or not energy has weight?

PART II: Does energy (light) take up space?

Fill a measuring cup with water up to the 150 milliliter mark.
Shine the flashlight on the water for 5 minutes.

3. Observe the water level very carefully as you shine the light on the water. record any changes in the water level.

4. Experiment by varying the length of time the light shines on the water. Try using a stronger source of light.

From your experiments, what can you conclude about energy taking up space?

6. Why might this not be a very good experiment to determine whether or not energy takes up space?

WHAT MAKES IT MOVE?

Materials:Various types of toys that move such as: wind-up toys, cars. trucks, etc), battery operated toys (cars. trucks, etc), air powered toys (balloons, rockets, etc) "gravity operated" toys (balls, yo-yo. etc.)

Operate (play with!) the toys at your lab station. Observe what they do. Describe what they have in common.

List each toy and describe what makes it move.

What would you call what makes all of these toys move?

WHAT MAKES IT MOVE?

IDEA:PROCESS SKILLS:

Energy is the ability to do work.Observing

If an object begins moving, thenCommunicating work is being done on that object.

LEVEL: TEACHERDURATION: 20-25 min.

STUDENT BACKGROUND:While this first activity does not require any background, it is an excellent

opportunity to determine the backgrounds of the students. Their responses

to the questions will indicate their level of understanding of what energy is

and may also identify many misconceptions about energy.

ADVANCE PREPARATION:Collect an assortment of toys that move. This can be done by asking students to bring in toys. asking friends with children to donate discarded toys, etc. If a toy requires operating instructions, these can be written on cards that can be placed on the tables with the toys. For example, an instruction to "Inflate the balloon (without tying a knot) and release it," would be helpful to show it as a toy that moves.

MANAGEMENT TIPS:The most important elements of this activity are allowing the students to observe and, using the summary discussion, help them formalize what they have observed. It is doubtful that many groups will just come up with the answers suggested below. A more typical answer to, "What makes it move?" for the case of the wind up toy would be "The spring." Follow-up questions by the instructor should lead them to what is in a spring that makes it move. The discussion should offer the opportunity to address the naive idea that the terms "energy" and "force" are interchangeable.

RESPONSES TO

SOME QUESTIONS:1. They all move.

Chemical energy, elastic potential energy, etc.
Energy

POINTS TO EMPHASIZE IN

THE SUMMARY DISCUSSION: 1. Energy is the ability to do work. If an object begins moving, then work is being done on that object A more complete definition of work is given in section IB.

Energy is not a thing, but rather a property that an object can have.
The terms "energy" and "force" are not interchangeable.

POSSIBLE EXTENSIONS:Continue this discussion by observing anything that moves. Discussion can be stimulated by showing pictures of people running, moving cars, sailboats, etc.

FOCUS ON PHYSICS - DEFINING ENERGY
(Discussion)

Discussion "Defining Energy"

Energy is a word like art, love or patriotism. You can think of lots of examples, but it is very difficult to come up with a precise definition. We can get a handle on the problem, however, by defining it in terms of some-thing that can be measured, work. Energy is the ability to do work. (This is an example of an operational definition).

The word work means different things to different people. When used in its scientific sense, it is defined as the product of an applied force on an object and the distance the object moves in the direction of the force, that is:

Work = Force x Distance moved in the direction of the force, or: W = F x d

Forces can be measured with a spring scale in units called Newtons. Distances can be measured with a ruler in meters. Once determining force and distance it is a simple matter to calculate the work that takes place in many situations. The activity that occurs when work takes place is the result of the energy that is transferred from one body to another in the process. The work done is numerically equal to the energy transferred.

Discussion. "Work and Energy Units"

Most upper elementary science programs use the metric system of measurement for their examples and problems. Forces are measured in Newtons and distances are measured in meters. The unit for work, then, is the Newton-meter (F x d). The same unit can also be used for measuring energy.

Scientists decided to honor one of the early investigators of the concept of energy. Sir James Prescott Joule (1818-1889) by giving the Newton-meter a nickname, the joule.

1 Newton-meter= 1 joule

Work and energy, then, can be expressed in Newton-meters, or joules. Some other common units of work and energy are:

kilowatt-hour (kwh) = 3,600,000 joules, used often to measure electrical energy.

calorie (cal) - 4.186 joules

kilocalorie (kcal) = 1000 calories = 4,186 joules. The Caloric used to measure the energy in foods should be written with a capital "C" to indicate that it is really a kilocalorie or 1000 calories. Thus a 1 Calorie diet soft drink is 1 kcal (1000 calories) and a 500 Calorie dessert is 500 kcal (500,000 calories).

An interesting activity is to have a student who travels overseas bring back a "Diet Coke" can from the country they visit. In France, they say 1 kilocalorie, and in Australia, they say "Low Joule Cola?

HOW IS WORK and / or ENERGYMEASURED?

Materials:bricks, board, meter stick, spring scale (that reads in Newtons), object (roller skate or car), string

1. Using books or blocks make a ramp with the board as shown in the illustration above.

2. a) Measure the force necessary to pull your object at a constant speed on a flat surface. ______Newtons

b) Measure the force necessary to pull your object at a constant speed up the ramp. ______Newtons

c)Measure the force necessary to pull your object straight up (vertical) at a constant speed. ______Newtons

3. Compare the results and explain ______

4. Measure the distance along the ramp, where the back wheels move as the skate is pulled from the bottom to the top of the ramp. (i.e. measure the distance from the back wheels at the bottom of the ramp to the back wheels at the top of the ramp.)

METERS ______

5. Calculate the work done in pulling the object up the ramp.

WORK = FORCE x DISTANCE ______Joules = ______Newtons x ______meters

6. Calculate the work done in lifting the object the same distance vertically as it was previously raised by pulling it up the ramp.

WORK = FORCE x DISTANCE ______Joules = ______Newtons x ______meters

7. Compare the work done in pulling the object up the ramp to the work done lifting the object the same distance vertically.

Work done in pulling the object up the ramp. ______Joules