Physical Science Genre Nonfiction Comprehension Skill Main Idea and Supporting Details Text Features • • • • Captions Charts Call Outs Glossary Science Content Energy Scott Foresman Science 3.13 ISBN 0-328-13844-4 ì<(sk$m)=bdie j< +^-Ä-U-Ä-U by Ann J. Jacobs Vocabulary What did you learn? Energy absorb potential energy 1. What kind of energy is stored in a battery? electric charge reflect electric circuit refract 2. While running in place, the chemical energy stored in your body would change to what kind of energy? electric current thermal energy kinetic energy Photographs: Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Unless otherwise acknowledged, all photographs are the property of Scott Foresman, a division of Pearson Education. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R) Background (Bkgd) Opener: ©Scott T. Smith/Corbis; Title Page: ©Spencer Grant/PhotoEdit; 2 ©Martin F. Chillmaid/Photo Researchers, Inc.; 3 ©Doug Wilson/Alamy Images; 4 ©Brad Wrobleski/Masterfile Corporation, ©Stone/Getty Images; 5 ©Fotopic/Index Stock Imagery; 6 (CC) ©AGStockUSA, Inc./Alamy Images, (CR) ©Henryk T. Kaiser/Index Stock Imagery; 7 (CL) ©Lester Lefkowitz/Corbis, (CCL) ©Mark L. Stephenson/ Corbis, (CC) ©Mark C. Burnett/Photo Researchers, Inc.; 8 ©Ted Grant/Masterfile Corporation; 14 (CL) ©Jeff Greenberg/Index Stock Imagery, (B) ©Norbert Wu Productions; 15 ©Pierre Arsenault/Masterfile Corporation; 16 ©Daryl Benson/Masterfile Corporation; 17 ©Craig Tuttle/Corbis; 19 ©Joel Sartore/ NGS Image Collection; 23 (CLT) ©Alan Schein Photography/Corbis, (CL) ©DK Images, (CLB) ©Martin F. Chillmaid-Spencer Grant/Photo Researchers, Inc. ISBN: 0-328-13844-4 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, write to: Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05 by Ann J. Jacobs 3. Why does rubbing a balloon attract pieces of paper? 4. In this book you have read about thermal energy. Write to explain how thermal energy moves. Use examples from the book in your answer. 5. Main Idea and Supporting Details What is the main idea of the last paragraph on page 2? What details support it? What is energy? Stored Energy Energy into another kind of energy to do work or cause a Energy is the ability to do work or cause change. Stored energy is potential energy. It can change change. Work is when force causes an object to move. Most of Fuel, such as natural gas, has potential energy. our energy comes from the Sun. The Sun heats Earth. Long ago, plants made food using energy from the The Sun’s light energy makes plants grow. Sun. The plants died and turned into fossils that are We use many other forms of energy too. Sound energy comes from a CD player. Chemical energy runs a car’s engine. Electrical energy runs many things in this kitchen. used as fuel. When we burn this fuel, we free potential energy. Work is possible. When you use batteries, you release potential energy. The stored energy in food, fuels, and batteries is chemical energy. Batteries and gasoline both contain stored energy. 2 3 Energy of Motion Potential energy can change to kinetic energy. Kinetic energy is the energy of motion. A car burns gas. The potential energy stored in the gas changes to kinetic energy. The car moves. A skier rests at the top of a hill. He has potential energy. Then he slides down the hill. His potential energy changes to kinetic energy. A skier uses a lot of energy. But he can replace it by eating food. The gas a car burns to create energy cannot be easily replaced. “Fossil” fuels, such as gas, are not renewable. 4 5 People use machines to change forms of energy How does energy change form? too. An electric toothbrush sits in a base that plugs into an electric outlet. The toothbrush’s battery stores electrical energy as chemical energy. The chemical Changing Forms of Energy energy changes to electrical energy when you turn on Energy changes from one form to another all the time. Your body stores potential energy in the form the toothbrush. The electrical energy then changes to mechanical energy as the toothbrush moves. of chemical energy. This chemical energy changes to kinetic energy when you move. Using Energy The kinetic energy of your arm cannot make a light bulb burn bright. But it can be used to flip a light switch. This changes Forms of Energy ;dgbhd[:cZg\n electrical energy to light energy. But not all the energy Chemical 8]Zb^XVa Mechanical BZX]Vc^XVa Electrical :aZXig^XVa Light A^\]i Thermal I]ZgbVa I]^hZcZg\n ]daYhi]Z eVgi^XaZhd[ bViiZg!hjX]Vh [ddY!id\Zi]Zg# I]Vi¼hl]n ZVi^c\[ddY\^kZh jhZcZg\n# I]^h^hi]Z ZcZg\nd[ bdk^c\i]^c\h# Bdk^c\eVgihd[ bVX]^cZh]VkZ i]^h`^cYd[ ZcZg\n# I]^hZcZg\nXVc eVhhi]gdj\] bZiVal^gZh#LZ jhZi]^h`^cYd[ ZcZg\nidgjc Veea^VcXZh# LZhZZi]ZHjc¼h ZcZg\n^ci]^h [dgb#EaVcihjhZ a^\]iidbV`Z [ddY#LZ X]Vc\Zdi]Zg [dgbhd[ZcZg\n ^cida^\]ihdlZ XVchZZ# I]^hZcZg\n bV`ZheVgi^XaZh d[bViiZgbdkZ [VhiZg#LZ[ZZa i]^hZcZg\nVh ]ZVi# gets changed. Some energy is given off as heat. The light bulb gets hot. 6 7 Ways That Energy Travels Parts of a Wave Energy can move from one place to another. How much energy does a wave have? How far A moving object, such as a ball, has energy. You the wave is from its midpoint shows its energy. You can feel the energy when you catch the ball. measure the distance from the midpoint of the wave Energy can also travel as waves. The waves are to the high or low point of the wave. The top of a shaped similar to the waves on a moving rope. Look wave is called a crest. The bottom is called a trough. at the rope on the next page. It is moving from side Wide waves have lots of energy. Narrow waves have to side. Energy makes this happen. It moves from one less energy. end of the rope to the other. Light and other forms of kinetic energy move as waves. Bigger waves carry more energy. You should also look at the length of a wave. The wavelength can be the measurement from the top of one crest to the top of the next crest. Short waves have more energy. Long waves have less energy. Ocean waves carry energy. Wavelength Midpoint Crest Distance from midpoint of wave 8 Trough Distance from midpoint of wave 9 What is heat energy? Sources of Heat Heat Energy form to another. The burner under the pot below Matter is made up of moving particles. Particles move because they have energy. The energy of moving particles in matter is called thermal energy. Thermal energy moves as heat. It moves from hot things to cool things. Put a spoon into a hot drink. Heat is given off when energy changes from one changes electrical energy to heat. A burning match changes chemical energy to heat. Try rubbing your hands together. The friction caused by rubbing gives off heat. There is heat every time energy moves. Heat from the drink moves through the cool spoon. Soon the spoon is as warm as the drink. The flow of energy stops when the drink and spoon are the A burning match is very hot! same temperature. Heat moves from the water to the frozen vegetables. 10 11 Effects of Heat on Matter Water evaporates if more heat is added to it. The Heat energy affects matter. You can measure the water turns into a gas called water vapor. Liquid water effect of heat on matter. Put some ice out in a room changes in another way at 100°C (212°F). Heat makes that is steady at a temperature above 0ºC (32ºF). the water boil. The water takes up more space when Look at the ice a few times during the hour. Measure it boils. Then it evaporates and becomes a gas. Hot and record the amount of ice that has melted. Record bubbles of gas float to the top of the water. Hot water the time when all the ice has melted. Record the droplets called steam come out of the bubbles. temperature. Time is one way to measure how this heat energy changed the ice. This water is boiling. Some of the water is leaving as steam. How has this ice changed? 12 13 Electricity gives us light. It makes the wire in a What is light energy? light bulb hot. The hot wire glows and gives off light. Sources of Light Most things that give off light give off heat too. Most energy comes from the Sun. The Sun’s energy reaches Earth as waves. The waves have different amounts of energy. Some of these waves affect us. We can see and use light energy. The Path of Light Light moves in all directions from where it starts. It moves away from its source in straight lines. Light moves this way until an object stops it. Light cannot Chemical changes also make light. Gas in the lamp below gives off light as it burns. The fish below gives go around objects. Objects that get in the way of light’s path cause shadows. off light too. Chemical changes in the fish’s body make light. The lamp and this fish are both a source of light. 14 15 How Light Changes Look closely at the picture below. The drops of water refract, or bend, light. This makes the light change Not all objects block light. Light can pass through some things, such as a window. All objects reflect light. This means light bounces direction. This can change the way things look. Each drop of water refracts light from the flower. Little pictures of the flower form as the light bends. off the object and moves in a different direction. Some things, such as a lake, reflect light better than other things. Why? They have flat and smooth surfaces. This makes the reflected light move in the same direction. Mountains and trees are reflected in this lake. 16 17 Light passes through things at different speeds. This Light is made of many colors. When light hits causes the light to refract. Light moves more slowly objects, they absorb some of the light. To absorb in water than air. The straw in the glass below looks means to take in. The rest of the light is reflected. broken because the water slows down and bends Things absorb and reflect different colors of light. If the light. something looks white, it is reflecting all the colors of Refraction can cause light to separate. When this sunlight. If something looks black, it is absorbing all happens you can see a rainbow. A rainbow shows the the colors of sunlight. Absorbed sunlight often turns to many colors of light. heat. This is why dark objects feel warm in sunlight. Green light has changed this white chicken to a green chicken. Why does this straw appear broken? 18 19 Positive and negative charges attract. The negative What is electrical energy? charge moves toward the positive charge. You may Electric Charges get a shock when you touch a person. If so, negative Matter is made up of particles that have electric charges. An electric charge is a small bit of energy. charges jumped between the two of you. The attraction between opposite charges can make An electric charge can be positive or negative. Matter things stick together. That’s why paper sometimes with mostly negative charges has a negative charge. sticks to a balloon. Matter with mostly positive charges has a positive charge. Matter with the same number of negative and The same charges repel each other. Objects with the same charge push each other away. positive charges has no charge. This balloon has no charge. It does not attract any pieces of paper. 20 This balloon has a charge. It attracts pieces of paper with an opposite charge. 21 Electric Currents and Circuits We need to make a lot of electricity because we use it every day. We have learned how to change energy Electric current is the movement of electrical into electricity. We can change the energy of moving energy or electric charge from place to place. water into electricity. We can change the energy of Lightning is an electric current that moves in any burning coal into electricity. We can turn the energy of direction. Electric current must follow a path heat and sunlight into electricity. What would modern to be useful. Electric current can make lights and life be like without electricity? CD players work. The path that a controlled electric current flows through is an electric circuit. Energy cannot flow if the path, or circuit, is broken. Look at How Electrical Energy Changes Form Light :aZXig^X^ineVhhZhi]gdj\]WjaWh#7jaWh X]Vc\ZZaZXig^XVaZcZg\n^cida^\]i# I]^h]ZaehjhhZZVic^\]i# Heat :aZXig^X^ineVhhZhi]gdj\]Xd^ah^c]ZViZgh# 8d^ahX]Vc\ZZaZXig^XVaZcZg\nid]ZVi# =ZVi`ZZehjhlVgbVcYaZihjhXdd`[ddY# Sound :aZXig^X^ineVhhZhVgdjcYVbV\cZi#I]Z bV\cZiX]Vc\ZhZaZXig^XVaZcZg\nid k^WgVi^dch^cVgVY^dheZV`Zg#I]ZclZXVc ]ZVgbjh^X# the picture below. The switch must be closed for the electricity to flow. Electricity flows through the circuit to light the light bulb when the switch is closed. Energy source Light bulb Switch 22 23 Glossary Vocabulary absorb absorb electric charge electric charge electric circuit electric circuit electric current kinetic energy electric current What did you learn? potential energy to take in reflect 1. What kind of energy is stored in a battery? the path that a controlled 2. While running in place, the chemical energy stored in your body would change to what kind of energy? the movement of electrical 3. Why does rubbing a balloon attract pieces of paper? a small amount of energy refract thermal energy electric current flows through energy or electric charge from 4. In this book you have read about thermal energy. Write to explain how thermal energy moves. Use examples from the book in your answer. 5. Main Idea and Supporting Details What is the main idea of the last paragraph on page 2? What details support it? one place to another kinetic energy the energy of motion potential energy stored energy reflect to bounce light off an object and have it travel in a different Photographs: Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Unless otherwise acknowledged, all photographs are the property of Scott Foresman, a division of Pearson Education. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R) Background (Bkgd) Opener: ©Scott T. Smith/Corbis; Title Page: ©Spencer Grant/PhotoEdit; 2 ©Martin F. Chillmaid/Photo Researchers, Inc.; 3 ©Doug Wilson/Alamy Images; 4 ©Brad Wrobleski/Masterfile Corporation, ©Stone/Getty Images; 5 ©Fotopic/Index Stock Imagery; 6 (CC) ©AGStockUSA, Inc./Alamy Images, (CR) ©Henryk T. Kaiser/Index Stock Imagery; 7 (CL) ©Lester Lefkowitz/Corbis, (CCL) ©Mark L. Stephenson/ Corbis, (CC) ©Mark C. Burnett/Photo Researchers, Inc.; 8 ©Ted Grant/Masterfile Corporation; 14 (CL) ©Jeff Greenberg/Index Stock Imagery, (B) ©Norbert Wu Productions; 15 ©Pierre Arsenault/Masterfile Corporation; 16 ©Daryl Benson/Masterfile Corporation; 17 ©Craig Tuttle/Corbis; 19 ©Joel Sartore/ NGS Image Collection; 23 (CLT) ©Alan Schein Photography/Corbis, (CL) ©DK Images, (CLB) ©Martin F. Chillmaid-Spencer Grant/Photo Researchers, Inc. direction refract to bend light thermal energy the energy of moving particles in matter ISBN: 0-328-13844-4 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, write to: Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05 24
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