Physical Science

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