Section 2: Newton S Laws of Motion (P. 145)

Section 2: Newton’s Laws of Motion (p. 145)

1. In 1686, published Principia,

a work explaining laws to

help people understand how forces relate to the

of objects.

Newton’s First Law of Motion (p. 145)

2. What is Newton’s first law?

3. An object in motion would keep moving forever if it never ran

into another object or an unbalanced force. True or False?

(Circle one.)

4. is the unbalanced force that slows

down sliding desks, rolling baseballs, and moving cars.

5. How does inertia explain why it would be so difficult to play

softball with a bowling ball?

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44 HOLT SCIENCE AND TECHNOLOGY

Chapter 6, continued

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DIRECTED READING WORKSHEETS 45

Newton’s Second Law of Motion (p. 148)

6. What is Newton’s second law of motion?

7. Look at the Environment Connection in the upper right of

page 148. A small car with a small engine cannot accelerate as

well as a large car with a large engine. True or False? (Circle one.)

8. An object’s acceleration decreases as the force on it increases.

True or False? (Circle one.)

9. Force equals times

10. The watermelon in Figure 16, on page 149, has more

and than the

apple, so the watermelon is harder to move than the apple.

Review (p. 149)

Now that you’ve finished the first part of Section 2, review what

you’ve learned by answering the Review questions in your

ScienceLog.

Newton’s Third Law of Motion (p. 150)

11. What is Newton’s third law of motion?

12. The phrase “equal and opposite” means that the action force and

the reaction force have the same

but act in opposite .

Chapter 6, continued

CHAPTER 6

13. What action and reaction forces are present when you are sitting

on a chair?

14. In a force pair, the reaction and action forces affect the same

object. True or False? (Circle one.)

15. When a ball falls off a ledge, gravity pulls the ball toward Earth

and also pulls Earth toward the ball. True or False? (Circle one.)

Momentum Is a Property of Moving Objects (p. 152)

16. Why does it take longer for a large truck to stop than it does for

a compact car to stop, even though they are traveling at the

same velocity and the same braking force is applied?

17. Momentum depends on the and

of an object.

18. In Figure 19, on page 152, during the collision, the momentum

of the cue ball

a. is added to the total momentum.

b. is transferred to the billiard ball.

c. is transferred to the table holding the balls up.

d. stays with the cue ball.

19. The law of conservation of momentum states that any time two

or more objects interact, they may exchange momentum, but the

total amount of momentum stays the same. True or False?

(Circle one.)

Review (p. 153)

Now that you’ve finished Section 2, review what you’ve learned by

answering the Review questions in your ScienceLog.

Name ______Date ______Class______