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Copyright © 2003 McGraw-Hill Ryerson Limited

Mrs. Sample

Holy Cross Collegiate

Science 24

Science 24

Chapter 5: Energy Conversions

In this chapter you will learn:

How to identify different types of energy

That some energy conversions absorb energy and others release it

How energy is converted and what is lost with each energy conversion

About the law of conservation of energy

Getting Ready1. List three kinds of energy used around the home.

2. Is all the energy that goes into a mixer used to mix the food in the bowl?

3. Much of the energy that goes into a dragster is not used to move it down the track. Suggest two other ways the energy is used.

Energy TransferDevelop an Energy Transfer flowchart that uses a series of circles around a central point. At the centre, place the title: Energy I Use. List five ways you use energy in the first ring. List the source of each kind of energy in the second ring. List where each of these energies came from in the third.

5.1 EnergyEnergy is the ability to ___________________. It can cause __________________ to the ___________________, ____________, ____________, or ________________ of an object.

Where does your body get its energy?

The human body converts stored (_______________) energy in food into other forms of energy. Eating the right food provides you with energy

Exercise speeds up the release of __________________ energy from food stored in the muscles

Sleep gives the body’s cells a chance to ________________________________ and _________________________ of energy

Using Energy to Do Work

You use ____________________ and ___________________ energy throughout the day.

In the morning, you depend on _______________________ when you turn on a light as you get out of bed

At breakfast, you count on __________________________ from the food you eat to fuel your body

Potential energy becomes useful when:

_________________________ is converted to ______________________ to illuminate your room

The _______________________ in food is converted to _____________________ as you walk out the door

Other examples?

Homework: page 83 # 1-2

5.2 Many Forms of EnergyWe could not live without the many ________________________ that provide us with food, heat, and light. Without energy from the Sun or _____________________, life on Earth ____________________________.

Green plants use ______________________ to produces a ______________ called __________________. Plants use the ________________ from the ________________ in their own growth. Animals cannot get energy ___________________________. When they eat plants, they use __________________________ to fuel their own bodies.

We use ___________ solar energy when we burn wood. Trees use the energy produced in leaves to make new cells we call wood. A campfire produces ________________________. Thermal energy provides _______________. Heat is produced when the _____________________ in substances around the flame ______________________________________. Like firewood, ______________________ such as crude oil and natural gas contain ___________________ from the Sun. This energy came from ______________________________ that died more than 100 million years ago.

Some homes have ________________________ that convert _______________________ directly to ______________________.

Other common sources of energy include _______________________ and ______________ ______________. Windmills capture ___________________________ from winds. As the wind vanes turn, the windmill _____________________ electric energy.

Alberta has many sites where ____________________________________ comes close to the surface. This ___________________________ is a source of ____________________. It __________________________________.

Homework: page 85 # 1-3

5.3 Understanding Energy ConversionsIn order to do work, _____________________________________ from one form to another. Scientists use specific terms to describe what happens during this process.

Energy that _______________ the system is called ______________________ The system where _____________________________ from one form into another

is called a ____________________ The energy that ______________ the system is called ________________________

Chemical Conversions

The heat you feel during exercise is produced by a _________________________ within the muscles of your body. _______________________ from food is ____________________ to ________________________. Many chemical reactions produce thermal energy.

When is Thermal Energy Wasted?

You have learned that thermal energy is _________________ during most activities. In many cases, this energy is ____________________. It is not used or needed for the activity. In some cases, such as during moderate physical activity, the _______________________ is not a problem, but it can become a problem on extremely hot days,

when athletes may get ____________________.

Many machines also produce ________________________. The thermal energy produced by many machines often _____________________ with their operation. The student using the drill press must be careful to _____________________________ the drill, for example. This could result in a piece of work with burn marks.

Other examples?

CHAPTER 5BLM 5–3

INFORMATION HANDOUT/ SKILL BUILDER

Energy Conversions in a Muscle Cell

Name: Date:

Use this worksheet to assist you with the information found on page 86.• Use this information to help you answer the questions that follow.• File this worksheet in the correct section of your notebook.

What To DoIt takes several energy conversions to convert the chemical energy in glucose into the energy needed to contract an arm muscle.

Step 1

Energy conversion occurs at the cellular level. Glucose is transported to the muscle cells by the blood. Glucose is converted in the cell mitochondria. What results is a form of chemical potential energy that the muscle tissues can use.

1. Identify the energy conversions at the cellular level.

input energy converter output energy

__________ ________ __________

input energy = ______________________

converter = ______________________

output energy = ______________________

CHAPTER 5BLM 5–3

INFORMATION HANDOUT/ SKILL BUILDER

Energy Conversions in a Muscle Cell (continued)

Step 2

The chemical potential energy formed in Step 1 is converted into kinetic energy by the muscle tissue. The kinetic energy becomes apparent when the muscles contract and the bones move.

2. Identify the energy conversions by the muscle cells.

input energy converter output energy

__________ ________ ___________

input energy = ______________________

converter = ______________________

output energy = ______________________

CHAPTER 5BLM 5–5

SCIENCE INQUIRY Energy Conversions Are Hardto Escape

Name: Date:

Use this worksheet to record your responses for Think & Link Investigation 5–C: Energy Conversions Are Hard to Escape.

Study each of the visuals in your textbook. For each visual, identify the converter, the form of input energy, and the form of output energy. Decide and record whether thermal energy is lost or gained. Answer the questions that follow in your Science Log or notebook. File this worksheet in the correct section of your notebook.

Picture The Converter Kind of Input Energy

Kind of Output Energy

Is Thermal Energy Given

Off?Example flashlight chemical energy

(battery)light energy (bulb)

yes

A. Person paddlingB. Snowblower engine workingC. Drill press cuttingD. Hobby rocket taking offE. Person using a trampolineF. Person eating a sandwich

Analyze1. In these examples, are some types of output energy more common than others? Explain.

2. In many energy conversions, some thermal energy (heat) is dissipated. When could thermal energy in these six examples be considered wasted energy? Explain.

5.4 Conservation of EnergyWhat types of energy are produced by a blow dryer?

______________________ provides the heat to dry your hair

There is _______________________ in the moving air Some electricity is converted to

________________________ The glowing elements produce _______________________ The fan that moves the air is a motor. ____________

produces __________________ that is not used to dry your hair.

You could measure the ____________________ that goes into the blow dryer. If you compared it to all these forms of ___________________, you would find that the two are equal. _________________________________________________________.

Scientists refer to this understanding as the ____________________________________.

The Law of Conservation of Energy states:

Another way of thinking about this is to compare energy to money. Imagine you had $10 in assorted coins. When you counted the coins a few days later, you noticed that you did not quite have $10. Likely, you would begin searching in your pockets, under the couch cushions, and around the house until you found the missing change.

Energy is like this. It does not just disappear. If some energy appears to be missing, it is because you have not ________________________________________________________.

Homework: page 93 # 1-2

CHAPTER 5BLM 5–6

SCIENCE INQUIRY Paired Pendulums

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Name: Date:

Use this worksheet to assist you with Find Out Activity: Do Swinging Pendulums Demonstrate the Law of Conservation of Energy? Use the boxes below to make six sketches of approximately how high each pendulum is swinging

after 5, 10, 15, 20, 25, and 30 seconds. You may need to stop the pendulums and restart the timing several times to allow time for sketching.

Answer the What Did You Find Out? questions that follow. File this worksheet in the correct section of your notebook.

Sketches of Swinging Pendulumsafter 5 seconds after 10 seconds

after 15 seconds after 20 seconds

after 25 seconds after 30 seconds

CHAPTER 5BLM 5–6

SCIENCE INQUIRY Paired Pendulums (continued)

What Did You Find Out?1. What happened to the second pendulum when the first one started to swing?

2. Did the first pendulum continue swinging?

3. Did the second pendulum swing at about the same height as the first?

4. Explain how this pendulum activity demonstrates the Law of Conservation of Energy.

5. (a) When did the pendulum have its greatest potential energy?

(b) When did it have its greatest kinetic energy?

6. Why is the first pendulum not able to return to its original height?

5.5 Energy Conversion SystemsTouch the hood of a car that has been for a long drive. The hood is hot. When you touch a light bulb that has been on for a while, it is hot enough to burn your fingers. Car engines and light bulbs are designed to

_______________________________________________. As well as running a car and lighting a room, both ______________ some of their ______________________________ to ______________________________________.

Gasoline engines produce a lot of _________________ and __________________ energy, as well as the wanted ________________ energy. Only about one third of the __________________________ energy of the gasoline that goes into a car engine is used to move the car. No

wonder people want cars that convert energy more _______________.

All machines convert some _______________ in ways that we ________________________________. Even electric motors ______________ a little energy to _____________ and _________________. Although the amount of _____________________ equals the amount of ____________________, some of the ___________________ in all machines is ______________________.

Homework: page 95 # 1-2

CHAPTER 5BLM 5–7

VOCABULARY CHECK Forms of Energy Crossword

Name: Date:

Complete the crossword below using the clues provided. You may refer to your textbook.

Across5. understanding that makes sense out

of energy7. energy produced when coal

combusts8. energy of position

11. energy that goes into a converter

Down1. name for specific type of energy in a

hot spring2. air with kinetic energy3. energy from the Sun4. energy of movement6. energy produced by two mixed

substances that combine9. energy from a converter

10. ability to do work

Chapter 5 Review Questions1. Define the following terms.

a. Energy

b. Potential energy

c. Kinetic energy

d. Solar energy

e. Thermal energy

f. Wind energy

g. Geothermal energy

h. Input energy

i. Converter

j. Output energy

k. Chemical energy

l. Law of Conservation of Energy

2. List 3 examples of kinetic energy. (5.1)

1. ____________________ 2. ____________________ 3. ____________________

3. List 3 examples of potential energy. (5.1)

1. ____________________ 2. ____________________ 3. ____________________

4. List at least three types of energy you depend on when you are: (5.1, 5.2)

a. walking to school

1. ____________________ 2. ____________________ 3. ____________________

b. driving to the store

1. ____________________ 2. ____________________ 3. ____________________

c. turning on your computer

1. ____________________ 2. ____________________ 3. ____________________

d. listening to the radio

1. ____________________ 2. ____________________ 3. ____________________

5. List two ways the Sun’s energy is converted for use. (5.2)

1. ____________________ 2. ____________________ 3. ____________________

6. Is thermal energy a form of kinetic energy? Explain. (5.2)

7. What energy conversions take place from the eating of an apple to the energy used to throw a ball? (5.2)

8. Briefly explain how plants use energy from the Sun. What about animals? (5.2)

9. List eight forms of energy and give two examples of each. (5.2)

1. ____________________ 2. ____________________ 3. ____________________

4. ____________________ 5. ____________________ 6. ____________________

7. ____________________ 8. ____________________ .

10. What three components are necessary for an energy conversion? Briefly describe each one. (5.3)

11. Identify the energy conversions that take place in the following scenarios: (5.3)

a. When the inside of a car heats up when the car is left in the Sun.

b. When you paddle a canoe.

c. A model rocket taking off.

d. Drill press cutting a piece of wood.

12. List three examples of energy conversion in which heat is given off. (5.3)

1. ____________________ 2. ____________________ 3. ____________________

13. Give two examples of waste thermal energy that might cause a problem? (5.3)

14. List three kinds of energy that come from a blow dryer. (5.4)

1. ____________________ 2. ____________________ 3. ____________________

15. Most of the energy produced by a car engine is not used to make the care move. Where does the rest of the energy go? (5.4)

16. Use an example to explain the Law of Conservation of Energy. (5.4)

17. Explain why input energy is often greater than useful output energy. (5.5)

18. Sketch two machines that have not been discussed in this chapter but you are familiar with. On the sketch, identify where there is waste output energy. (5.5)

CHAPTER 5BLM 5–9

VOCABULARY CHECK Energy Conversions Word Search

Name: Date:

Complete the word search puzzle by finding the 12 key terms listed below. Circle the words as you find them.

Hint: The words may be hidden in any direction, but they will always be in a straight line.

chemical energyconservationconverter

energy (by itself)geothermalinput energy

kineticoutput energypotential energy

solarthermalwind

Z X C H E M I C A L E N E R G YC Y V O A S D D F G H J J K J GY G R E N E T U P N I A S D D RG R E A S S D H F F Y G R E N ER E Q O R E E T E Y U U I P O NE N N V T B B R V R R V V B N EN E G H J H H G V E M J H J J LE D U R Y T E Y T A T A Y Y U AT N Q R T Y T R R R T T L Y T IU I P O I O E T M T T I T S Y TP W A D F V D D F A I H O G D NT G G G N G H H G H L L G N H EU G F O G G L K F K A K I K J TO B C V B P B S B R B W V B N OZ V C X C C K I N E T I C C V P

Copyright © 2003 McGraw-Hill Ryerson Limited