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Chapter 11: Motion Section 11.1: Distance and Displacement
I. Choosing a Frame of Reference Group #_____
Main Idea:
Drawing_______________
A. How Fast Are You Moving? Group #_____
Main Idea:
Drawing_________________
B. Which Frame Should You Choose? Group #_____
Main Idea:
Drawing_________________
II. Measuring Distance Group #_____
Main Idea:
Drawing_________________
III. Measuring Displacements Group #______
Main Idea:
Drawing_________________
IV. Combining Displacements Group #______
Main Idea:
Drawing_________________
A. Displacement Along a Straight Line Group #_____
Main Idea:
Drawing________________
B. Displacement That Isn’t Along a Straight Path Group #_____
Main Idea:
Drawing_________________
Section 11.2: Speed and Velocity
I. Speed Group #_____
Main Idea:
Drawing_______________
A. Average Speed Group #_____
Main Idea:
Drawing________________
B. Instantaneous Speed Group #_____
Main Idea:
Drawing_________________
II. Graphing Motion Group #_____
Main Idea:
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III. Velocity Group #_____
Main Idea:
Drawing_________________
III. Combining Velocities Group #_____
Main Idea:
Drawing_________________
Section 11.3: Acceleration
I. What is Acceleration? Group #_____
Main Idea:
Drawing_________________
A. Changes in Speed Group #_____
Main Idea:
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B. Changes in Direction Group #_____
Main Idea:
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C. Changes in Speed and Direction Group #_____
Main Idea:
Drawing_________________
A. Constant Acceleration Group #_____
Main Idea:
Drawing_________________
II. Calculating Acceleration Group #_____
Main Idea:
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III. Graphs of Accelerated Motion Group #_____
Main Idea:
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A. Speed-Time Graphs Group #_____
Main Idea:
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B. Distance-Time Graph Group #_____
Main Idea:
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IV. Instantaneous Acceleration Group #______
Main Idea:
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Chapter 12: Forces and Motion Section 12.1: Forces
I. What is a Force? Group #_____
Main Idea:
Drawing_______________
A. Measuring Force Group #_____
Main Idea:
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B. Units of Force Group #_____
Main Idea:
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C. Representing Force Group #_____
Main Idea:
Drawing________________
II. Combining Forces Group #_____
Main Idea:
Drawing_________________
A. Balanced Forces Group #_____
Main Idea:
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B. Unbalanced Forces Group #_____
Main Idea:
Drawing_________________
III. Friction Group #______
Main Idea:
Drawing_________________
A. Static Friction Group #_____
Main Idea:
Drawing_________________
B. Sliding Friction Group #_____
Main Idea:
Drawing_________________
C. Rolling Friction Group #_____
Main Idea:
Drawing________________
D. Fluid Friction Group #_____
Main Idea:
Drawing_________________
IV. Gravity Group #______
Main Idea:
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A. Falling Objects Group #_____
Main Idea:
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V. Projectile Motion Group #______
Main Idea:
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Section 12.2: Newton’s First and Second Laws of Motion
I. Aristotle, Galileo, and Newton Group #_____
Main Idea:
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A. Aristotle Group #_____
Main Idea:
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B. Galileo Group #_____
Main Idea:
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C. Newton Group #_____
Main Idea:
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II. Newton’s First Law of Motion Group #_____
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III. Newton’s Second Law of Motion Group #_____
Main Idea:
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III. Weight and Mass Group #_____
Main Idea:
Drawing_________________
Section 12.3: Newton’s Third Law of Motion and Momentum
I. Newton’s Third Law Group #_____
Main Idea:
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A. Action and Reaction Forces Group #_____
Main Idea:
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B. Action-Reaction Forces and Motion Group #_____
Main Idea:
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C. Action-Reaction Forces Do Not Cancel Group #_____
Main Idea:
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II. Momentum Group #_____
Main Idea:
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III. Conservation of Momentum Group #_____
Main Idea:
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Section 12.4: Universal Forces
I. Electromagnetic Forces Group #_____
Main Idea:
Drawing_________________
A. Electric Forces Group #_____
Main Idea:
Drawing_________________
B. Magnetic Forces Group #_____
Main Idea:
Drawing_________________
II. Nuclear Forces Group #_____
Main Idea:
Drawing_________________
A. Strong Nuclear Force Group #_____
Main Idea:
Drawing_________________
B. Weak Nuclear Force Group #_____
Main Idea:
Drawing_________________
III. Gravitational Force Group #_____
Main Idea:
Drawing_________________
A. Gravity Acts Over Large Distances Group #_____
Main Idea:
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B. The Earth, Moon, and Tides Group #_____
Main Idea:
Drawing_________________
C. Satellites and Orbits Group #_____
Main Idea:
Drawing_________________
D. Uses of Satellites Group #_____
Main Idea:
Drawing_________________
Name ___________________________ Class ___________________ Date _____________
Chapter 11 Motion
Section 11.1 Distance and Displacement(pages 328–331)This section defines distance and displacement. Methods of describing motionare presented. Vector addition and subtraction are introduced.
Reading Strategy (page 328)
Predicting Write a definition for frame of reference in your own wordsin the left column of the table. After you read the section, compareyour definition to the scientific definition and explain why a frame ofreference is important. For more information on this Reading Strategy,see the Reading and Study Skills in the Skills and ReferenceHandbook at the end of your textbook.
Frame of Reference
Frame of reference probably means Frame of reference actually means
1. What two things must you know to describe the motion of an object?
Choosing a Frame of Reference (pages 328–329)
2. Is the following sentence true or false? A frame of reference is not necessary to describe motion accurately and completely.
3. What is a frame of reference?
4. Movement in relation to a frame of reference is called .5. Imagine that you are a passenger in a car. Circle the letter of the best
frame of reference you could use to determine how fast the car ismoving relative to the ground.
a. the people sitting next to you in the backseatb. the driver of the carc. a van traveling in the lane next to your card. a sign post on the side of the road
Measuring Distance (page 329)
6. Distance is .
7. Circle the letter of the SI unit best suited for measuring the length ofa room in your home.
a. kilometers b. metersc. centimeters d. millimeters
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Physical Science Reading and Study Workbook ■ Chapter 11 127
Sample answer: The range of distances orarea that you are considering in a problem
A system of objects that are not movingwith respect to one another
You must know the direction the object is moving and how fast the object is moving.
false
It is a system of objects that are not moving relative
to one another.
relative motion
the length of a path between two points
Measuring Displacements (page 330)
8. Is the following sentence true or false? Five blocks south is anexample of a displacement.
9. Compare and contrast distance and displacement.
10. What would your total displacement be if you walked from yourfront door, around the block, and then stopped when you reachedyour front door again?a. one block b. two blocksc. the entire distance of your trip d. zero
Combining Displacements (pages 330–331)
11. A vector is a quantity that has both and .
12. Circle the letter of each answer that could describe the magnitudeof a vector.a. length b. directionc. amount d. size
13. To combine two displacements that are in opposite directions, themagnitudes from one another.
For questions 14 and 15, refer to the figure below.
14. The magnitudes of the two displacement vectors areand .
15. Because the two displacements are in opposite directions, themagnitude of the total displacement is .
16. Circle the letter that answers the question. What is the displacementof a cyclist who travels 1 mile north, then 1 mile east, and finally1 mile south?a. 3 miles east b. 1 mile northc. 3 miles south d. 1 mile east
17. The vector sum of two or more other vectors is called the.
Name ___________________________ Class ___________________ Date _____________
Chapter 11 Motion©
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128 Physical Science Reading and Study Workbook ■ Chapter 11
true
Distance is the length of a path
between two points, whereas displacement is the direction from a starting point and the length
of a straight line from the starting point to the ending point.
magnitude
direction
subtract
7 km 3 km
4 km
resultant vector
7 km
3 km
0 1 2 3 4 5 6 7
Start Finish
Name ___________________________ Class ___________________ Date _____________
Chapter 11 Motion
Section 11.2 Speed and Velocity(pages 332–337)This section defines and compares speed and velocity. It also describes how tocalculate average speed.
Reading Strategy (page 332)
Monitoring Your Understanding After you read this section, identifyseveral things you have learned that are relevant to your life. Explainwhy they are relevant to you. For more information on this ReadingStrategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Facts About Speed and Velocity
What Is Important Why It Is Important
Speed (pages 332–334)
1. Define speed.
2. The SI units for speed are .
3. How is instantaneous speed different from average speed?
4. The equation used for calculating average speed is .5. Is the following sentence true or false? You can determine how fast
you were going at the midpoint of a trip by calculating averagespeed for the entire trip.
6. A student walked 1.5 km in 25 minutes, and then, realizing he waslate, ran the remaining 0.5 km in 5 minutes. Calculate his averagespeed on the way to school.
7. What type of speed does an automobile’s speedometer display?
Graphing Motion (page 334)
8. The slope of a line on a distance-time graph represents .
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Physical Science Reading and Study Workbook ■ Chapter 11 129
Sample answers shown below.
Average speed is distance dividedby time.
Instantaneous speed is differentfrom average speed.
Velocity is not the same as speed.
I could use this to calculate various speeds, like theaverage speed at which I travel getting to school.
You can’t use a single speedometer reading todetermine how long a trip will take.
This could be useful in giving directions or indescribing the path that you take on a walk.
–v � d/t
Speed is the ratio of the distance an object moves to the amount of time it moves.
meters per second (m/s)
Instantaneous speed is
measured at a particular instant, while average speed is computed for the entire duration of a trip.
false
–v � Total distance/Total time�(1.5 km � 0.5 km)/(25 min � 5 min)�2.0 km/30 min�2.0 km/0.5 h�4.0 km/h
A speedometer displays instantaneous speed.
speed
Name ___________________________ Class ___________________ Date _____________
Chapter 11 Motion©
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130 Physical Science Reading and Study Workbook ■ Chapter 11
For questions 9 through 11, refer to the graph below.
9. Draw a point on the graph that represents 200 m traveled in 4 seconds. Draw a line connecting this point with the origin (0,0).Label this as line A.
10. Draw a point on the graph that represents 100 m traveled in 10 seconds. Draw a line connecting this point with the origin (0,0).Label this as line B.
11. Calculate the average speed (slope) of lines A and B. Be sure toinclude units.
Velocity (page 336)
12. How do speed and velocity differ?
13. Circle the letter of each sentence that describes a change in velocity.a. A moving object gains speed.b. A moving object changes direction.c. A moving object moves in a straight line at a constant speed.d. A moving object slows down.
14. Is the following sentence true or false? If a car travels around agentle curve on a highway at 60 km/h, the velocity does notchange.
Combining Velocities (page 337)
15. How do velocities combine? 16. A river flows at a velocity of 3 km/h relative to the riverbank. A
boat moves upstream at a velocity of 15 km/h relative to the river.What is the velocity of the boat relative to the riverbank?a. 18 km/h downstreamb. 15 km/h upstreamc. 12 km/h upstreamd. 12 km/h downstream
Speed indicates distance traveled over a given amount
of time; velocity describes both speed and direction of motion.
false
Velocities combine by vector addition.
AB
200
400
300
100
0
Dis
tan
ce (
met
ers)
Time (seconds)
0 2 4 6 8 10
Distance-Time Graph
A: � 200 m/4 s � 50 m/s; B: � 100 m/10 s � 10 m/s–v –v
Name ___________________________ Class ___________________ Date _____________
Chapter 11 Motion
Section 11.3 Acceleration(pages 342–348)This section describes the relationships among speed, velocity, andacceleration. Examples of these concepts are discussed. Sample calculations ofacceleration and graphs representing accelerated motion are presented.
Reading Strategy (page 342)
Summarizing Read the section on acceleration. Then complete theconcept map to organize what you know about acceleration. For moreinformation on this Reading Strategy, see the Reading and Study Skillsin the Skills and Reference Handbook at the end of your textbook.
What Is Acceleration? (pages 342–345)
1. The rate at which velocity changes is called .
2. In terms of speed and direction, in what ways can an object accelerate?
3. Because acceleration is a quantity that has both magnitude anddirection, it is a(n) .
4. Is the following sentence true or false? Acceleration is the result ofincreases or decreases in speed.
5. Ignoring air resistance, a rock in free fall will have a velocity ofafter 4.0 seconds.
6. A horse on a carousel that is moving at a constant speed isaccelerating because .
7. Describe constant acceleration.
Calculating Acceleration (pages 345–346)
8. Write the equation used to calculate the acceleration of an object.
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Physical Science Reading and Study Workbook ■ Chapter 11 131
Acceleration
Speed Direction m/s2
is a changein
is measuredin units of
acceleration
It can change its speed, its direction, or both its speed and direction.
vector
true
39.2 m/s
its direction is constantly changing
Constant acceleration is a steady change in velocity.
Acceleration � Change in velocity/ Total time
9. Is the following sentence true or false? When the final velocity isless than the initial velocity of an object, the acceleration isnegative.
10. A skateboarder begins down a ramp at a speed of 1.0 m/s. After 3 seconds, her speed has increased to 4.0 m/s. Calculate her acceleration.
a. 1.0 m/s2 b. 3.0 m/s2
c. 5.0 m/s2 d. 9.8 m/s2
Graphs of Accelerated Motion (pages 346–348)
11. A speed-time graph in which the displayed data forms a straightline is an example of a(n) .
For questions 12 through 15, refer to the graphs below.
12. Graph A represents the motion of a downhill skier. How fast was the skier movingafter traveling down the hill for 2.5 seconds?
13. In which graph does an object move at constant speed during thefirst 4 seconds?
14. Graph B represents the motion of a mountain biker. What is the biker’s speed at times of 10 s and 20 s?
15. Determine the acceleration of the mountain biker during the 10 second to 20 second time period. Show your work.
16. The plotted data points representing acceleration in a distance-time graph form a(n) .
Instantaneous Acceleration (page 348)
17. The measure of how fast a velocity is changing at a specific instantis known as .
Name ___________________________ Class ___________________ Date _____________
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132 Physical Science Reading and Study Workbook ■ Chapter 11
10 m/s
5 m/s (at 10 s); 0 m/s (at 20 s)
true
linear graph
Graph B
� ( � )/ � (0 m/s � 5 m/s)/10 s � �0.5 m/s2
curve
instantaneous acceleration
8
20
16
12
4
0
Spee
d (
m/s
)
Time (s)0 1 2 3 4
Acceleration Graph A
2
5
6
7
4
3
1
0
Spee
d (
m/s
)
Time (s)
0 5 10 15 20
Acceleration Graph B
vf via t
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion
Section 12.1 Forces(pages 356–362)This section describes what forces are and explains how forces affect themotion of various objects.
Reading Strategy (page 356)
Relating Text and Visuals As you read about forces, look carefully at Figures 2, 3, and 5 in your textbook. Then complete the table bydescribing the forces and motion shown in each figure. For moreinformation on this Reading Strategy, see the Reading and StudySkills in the Skills and Reference Handbook at the end of your textbook.
Forces and Motion
Figure Is Net Force 0? Effect on Motion
2A
2B
3
5A
5B
What is a Force? (pages 356–357)
1. A force is defined as a(n) or a(n)that acts on an object.
2. Is the following sentence true or false? A force can act to cause anobject at rest to move or it can accelerate an object that is alreadymoving.
3. How can a force change the motion of an object that is already moving?
4. Circle the letter of the best answer. What force causes a 1-kg mass toaccelerate at a rate of 1 meter per second each second?a. 1 kg/m•s2 b. 1 kg/sc. 1 kg•m d. 1 newton
Combining Forces (pages 357–358)
5. The overall force acting on an object after all the forces are combinedis the .
6. How do balanced and unbalanced forces affect the motion of an object?
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Physical Science Reading and Study Workbook ■ Chapter 12 137
Yes None
Yes None
Yes None
Yes None
No Potted plant accelerates
pushpull
true
A force can accelerate a moving object by changing its speed, its direction, or both.
net force
When balanced forces act on an object, there is no change in the object’s motion because the net
force is zero. When unbalanced forces act on an object, the net force is not zero, so the object
accelerates.
Friction (pages 359–360)
7. Is the following sentence true or false? Friction is a force that helpsobjects that are touching move past each other more easily.
8. Circle the letters that identify types of friction.a. rolling b. gravityc. static d. sliding
9. The friction force that acts on objects that are at rest is.
10. Why is less force needed to keep an object moving than to startthe object in motion?
11. Complete the table below about friction forces.
Types of Friction Forces
Friction Force Example
Static
Pushing a book along your desk
Rolling
12. Is the following sentence true or false? Fluid friction is a force thatopposes the motion of an object through a fluid such as water.
Gravity (page 361)
13. Gravity is a(n) force that pulls objects together.14. Is the following sentence true or false? Earth’s gravity acts
downward toward the center of Earth. 15. Describe how gravity and air resistance affect the motion of a
falling object.
16. Is the following sentence true or false? Terminal velocity is theconstant velocity of a falling object when the force of air resistanceequals the force of gravity.
Projectile Motion (page 362)
17. The curved path caused by the combination of an initial forwardvelocity and the downward force of gravity is known as
motion.
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion©
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138 Physical Science Reading and Study Workbook ■ Chapter 12
Walking
Sliding
In-line skates
false
static friction
Sliding friction, which opposes a moving object, is less than the static
friction that acts on an object at rest, so less force is needed to keep an object moving.
true
attractive
true
Gravity causes an object to accelerate downward, whereas air resistance acts
opposite the direction of motion to reduce acceleration.
true
projectile
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion
Section 12.2 Newton’s First andSecond Laws of Motion(pages 363–369)This section discusses how force and mass affect acceleration. The accelerationdue to gravity is defined, and mass and weight are compared.
Reading Strategy (page 363)
Building Vocabulary As you read this section, write a definition inthe table for each vocabulary word you encounter. Use your ownwords in the definitions. For more information on this ReadingStrategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Matter and Motion
Vocabulary Definition
Inertia
Aristotle, Galileo, and Newton (pages 363–364)
Match each scientist with his accomplishment.Accomplishment Scientist
1. Italian scientist who did experiments that helped correct misconceptions about force and motion
2. Scientist who studied in England and introduced several laws describing force and motion
3. An ancient Greek philosopher who made many scientific discoveries through observation and logical reasoning
Newton’s First Law of Motion (pages 364–365)
4. Is the following sentence true or false? According to Newton’s firstlaw of motion, an object’s state of motion does not change as long asthe net force acting on it is zero.
5. What is inertia? © Pe
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Physical Science Reading and Study Workbook ■ Chapter 12 139
Mass Mass is the amount of matter an object contains as measured by its inertia.
Inertia is the tendency of an object to resist a change in its motion.
Weight Weight is the force of gravity acting on an object.
b
c
a
true
Inertia is the tendency of an object to resist changes in its motion.
a. Aristotleb. Galileo c. Newton
6. Is the following sentence true or false? The law of inertia statesthat an object in motion will eventually slow down and come to acomplete stop if it travels far enough in the same direction.
Newton’s Second Law of Motion (pages 365–368)
7. According to Newton’s second law of motion, acceleration of anobject depends upon the of the object andthe acting on it.
Match each term with its description.Description Term
8. A measure of the inertia of an object9. Net force/Mass
10. Causes an object’s velocity to change
11. Is the following sentence true or false? The acceleration of anobject is always in the same direction as the net force acting onthe object.
12. Is the following sentence true or false? If the same force acts upontwo objects with different masses, the acceleration will be greaterfor the object with greater mass.
Weight and Mass (pages 368–369)
13. What is weight?
14. Write the formula used to calculate the weight of an object.
15. Is the following sentence true or false? Because the weight formulashows that mass and weight are proportional, doubling the massof an object will not affect its weight.
16. Complete the table below by describing the difference betweenmass and weight.
Mass and Weight
Mass Weight
17. On the moon, the acceleration due to gravity is only about one sixththat on Earth. Thus, an object will weigh on the moon than it weighs on Earth.
Name ___________________________ Class ___________________ Date _____________
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140 Physical Science Reading and Study Workbook ■ Chapter 12
Measure of the inertia of an objectMeasure of the force of gravity actingon an object
false
mass
net force
a
c
b
true
false
Weight is the force of gravity acting on an object.
Weight � Mass � Acceleration due to gravity
less
false
a. massb. net forcec. acceleration
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion
Section 12.3 Newton’s Third Law ofMotion and Momentum(pages 372–377)This section describes action-reaction forces and how the momentum ofobjects is determined.
Reading Strategy (page 372)
Summarizing As you read about momentum in this section, completethe concept map to organize what you learn. For more information onthis Reading Strategy, see the Reading and Study Skills in the Skillsand Reference Handbook at the end of your textbook.
Newton’s Third Law (page 373)
1. According to Newton’s third law of motion, what happens whenever one object exerts a force on a second object?
2. The equal and opposite forces described by Newton’s third law arecalled and forces.
3. Circle the letters that identify each sentence that is true aboutaction-reaction forces.a. Newton’s second law describes action-reaction forces.b. Forces always exist in pairs.c. Action-reaction forces never cancel.d. All action-reaction forces produce motion.
4. Is the following statement true or false? Action-reaction forces donot cancel each other because the action force is always greater thanthe reaction force.
Momentum (pages 374–375)
5. Circle the letter of each factor that affects the momentum of amoving object.a. mass b. volume c. shape d. velocity
6. If two identical objects are moving at different velocities, the objectthat is moving faster will have momentum.
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Physical Science Reading and Study Workbook ■ Chapter 12 141
Momentum
kg•m/s
is measuredin
is calculated bymultiplying
Mass Velocity
The second object exerts an equal and
opposite force on the first object.
action reaction
false
greater
7. Your in-line skates are sitting in a box on a shelf in the closet. Whatis their momentum?
8. Is the following sentence true or false? An object with a small masscan have a large momentum if the object is traveling at a highspeed.
9. Write the momentum formula, including the correct units.
10. Circle the letter of the object that has the greatest momentum.a. a 700-gram bird flying at a velocity of 2.5 m/sb. a 1000-kilogram car traveling at 5 m/sc. a 40-kilogram shopping cart rolling along at 0.5 m/sd. a 300-kilogram roller coaster car traveling at 25 m/s
Conservation of Momentum (pages 376–377)
11. What does conservation of momentum mean?
12. Is the following sentence true or false? Objects within a closedsystem can exert forces on one another, but other objects and forcescannot leave or enter the system.
13. According to the law of conservation of momentum, what happens to the total momentum of a system if no net force acts on the system?
14. Is the following sentence true or false? In a closed system with twoobjects, the loss of momentum of one object equals the gain inmomentum of the other object.
For questions 15 and 16, refer to the graph below.
15. The momentum of the ball at one second is .16. What is the speed of the ball at 0.5 seconds? Show your
calculation. Hint: Solve the momentum formula for velocity.
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Chapter 12 Forces and Motion
142 Physical Science Reading and Study Workbook ■ Chapter 12
Time (s)
Mo
men
tum
(kg
m/s
)
4
3
2
1
00 0.5 1.0 1.5
Momentum of a 0.25-kg Ball
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reser ved.
zero
true
Momentum (kg•m/s) � Mass (kg) � Velocity (m/s)
Momentum does not increase or decrease.
true
The total momentum does not change.
true
2.5 kg•m/s
Momentum � Mass � Velocity; 1.25 kg•m/s � 0.25 kg � Velocity; Velocity � � 5 m/s1.25 kg•m/s
0.25 kg
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion
Section 12.4 Universal Forces(pages 378–382)This section defines four forces that exist throughout the universe. Each forceis described and its significance is discussed.
Reading Strategy (page 378)
Comparing and Contrasting As you read this section, compare twouniversal forces by completing the table. For more information on thisReading Strategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Universal Nuclear Forces
Force Acts on Which Acts Over RelativeParticles? What Distance? Strength
Strong nuclear
Weak nuclear
1. What are the four universal forces? a. b.c. d.
Electromagnetic Forces (pages 378–379)
2. Is the following sentence true or false? Electromagnetic force isassociated with charged particles.
3. Name the only two forces that can both attract and repel.
4. Objects with like charges one another, andobjects with opposite charges one another.
5. Circle the letters of the sentences that correctly describe magnets or magnetic forces.a. Magnetic forces act on certain metals.b. Magnets have two poles, north and south.c. Two poles that are alike attract each other.d. Magnetic forces can both attract and repel.
Nuclear Forces (pages 379–380)
6. The force that holds particles in the nucleus together is the .7. What evidence suggests that nuclear forces have a powerful
force of attraction?
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Physical Science Reading and Study Workbook ■ Chapter 12 143
Neutrons and protons
Very short Very strong (100 times stronger than electrical force)
All particles Short Weaker than the strong force
Strong nuclearElectromagnetic
GravitationalWeak nuclear
true
Electric and magnetic forces
can both attract and repel.
repelattract
strong nuclear force
These forces are strong enough to overcome the electric force of
repulsion that acts among the positively charged protons in the nucleus.
8. Circle the letter of the best answer. Over extremely short distances,approximately how many times stronger is the strong nuclearforce than the electric force of repulsion?a. 10 b. 100 c. 1000 d. 10,000
9. Compare and contrast the strong and weak nuclear forces.
Gravitational Force (pages 380–382)
10. State Newton’s law of universal gravitation.
11. Circle the letter of each sentence that is true about gravitational force.a. The closer two objects are to one another, the weaker the
gravitational force.b. The farther apart two objects are, the weaker the gravitational force.c. The greater the mass of an object, the stronger its gravitational force.d. Earth’s gravitational force is stronger than the gravitational
force of the sun.12. The gravitational force of attraction between two objects depends
on and .13. Is the following sentence true or false? Gravity is the weakest
universal force, but it is the most effective force over longdistances.
14. The sun’s mass is much greater than the mass of Earth, so the sun’s gravitational force is much than that of Earth.
15. Why does the moon orbit Earth in a nearly circular path?
16. Is the following sentence true or false? The gravitational pull of themoon is the primary cause of Earth’s ocean tides.
17. Is the following sentence true or false? An artificial satellite in ahigh orbit will slow down and lose altitude due to the pull ofEarth’s gravity.
18. List four uses of artificial satellites.
Name ___________________________ Class ___________________ Date _____________
Chapter 12 Forces and Motion©
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144 Physical Science Reading and Study Workbook ■ Chapter 12
Both forces act within
the nucleus of an atom to hold it together. The strong nuclear force affects only the neutrons
and protons in the nucleus and acts over extremely short distances. The weak nuclear force acts
over an even shorter distance but affects all particles, not just protons and neutrons.
Every object in the universe attracts
every other object.
distancemass
true
stronger
The moon’s inertia and
centripetal force from Earth produce the nearly circular path.
true
false
Students’ answers should include four of the following:
Satellites monitor Earth’s weather, create detailed radar maps of Earth’s surface, use telescopes
to gaze into space, study Earth’s climate, receive and transmit radio and microwave signals, receive
and transmit cell phone and satellite television signals.