Download 0BJECTIVES 7

0BJECTIVES 7.0-7.3 STUDY GUIDE
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. What is the speed of an object at rest?
a. 15 km/h
b. 0 km/h
c. 1 km/h
d. This cannot be determined without further information.
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2. A 10.0 kg dog chasing a rabbit north at 6.0 m/s has a momentum of
a. 0.6 kg m/s.
c. 60.0 m/s.
b. 60.0 kg m/s north.
d. 60.0 kg/s.
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3. A cyclist is traveling at an initial speed of 10.0 m/s. She accelerates at a rate of 0.500 m/s2. Find her final
speed after 9.0 s.
a. 14.5 m/s
c. 5.5 m/s
b. 14.5 m/s2
d. 5.5 m/s2
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4. A man pushes a crate along a factory floor by exerting a force of 55 N. If the crate moves a distance of 4.0 m,
how much work does the man perform?
a. 165 J
c. zero
b. 220 J
d. 145 J
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5. A boy pushes on a parked car with a force of 200 N. The car does not move. How much work does the boy do
on the car?
a. 200 N
c. zero
b. 200 J
d. can’t be determined
____
6. In order to determine speed, you must know
a. time.
b. distance.
c. Both (a) and (b)
d. None of the above
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7. What does it mean when a change in velocity is positive?
a. The object is speeding up.
c. The object is slowing down.
b. The object is changing direction.
d. The object is falling down.
____
8. The _____________ of ab object consists of its speed and its direction.
a. instantaneous speed
c. velocity
b. average speed
d. displacement
____
9. What are the units of power?
a. watts
b. horsepower
____ 10. The SI unit for acceleration is
a. mph.
b. ft/s2.
c. joules per second
d. All of the above
c. m/s2.
d. v / t.
____ 11. The law that states that the unbalanced force acting on an object equals the object’s mass times its
acceleration is
a. Newton’s first law of motion.
c. Newton’s third law of motion.
b. Newton’s second law of motion.
d. the law of conservation of momentum.
____ 12. What does it mean when a change in velocity is negative?
a. The object is speeding up.
b. The object is changing direction.
c. The object is slowing down.
d. The object is falling down.
____ 13. The average acceleration of a car that goes from 0 m/s to 25 m/s in 8.0s is
a. 0.32 m/s
c. 3.1 m/s
b. 0.32 m/s2
d. 3.1 m/s2
____ 14. Which of the following does not indicate velocity?
a. 14 m/s SSE
b. 40 km/h toward the town square along the main street
c. 80 km/h going from New York toward New Jersey
d. 28 km from Los Angeles to Catalina Island
____ 15. The difference between speed and velocity is that velocity includes
a. direction.
c. time.
b. distance.
d. weight.
____ 16. A pitcher throws a baseball to home plate, a distance of 60.5 feet. The ball reaches home plate in 0.63 s.
What is the velocity of the ball?
a. 38 ft/s
c. 96 ft/s
b. 38 ft/s toward home plate
d. 96 ft/s toward home plate
____ 17. How long does it take for a stone falling from a bridge with an average acceleration downward of 9.8 m/s2 to
hit the water. The stone starts from rest and hits the water with a velocity of 12.3 m/s.
a. 3.95 m/s
c. 3.95 m/s
b. 1.26 s
d. 39.5 m/s2
____ 18. The law that states that every object maintains constant velocity unless acted on by an unbalanced force is
a. Newton’s first law of motion.
c. Newton’s third law of motion.
b. Newton’s second law of motion.
d. the law of conservation of momentum.
____ 19. A cheetah can accelerate at up to 6.0 m/s2. How long does it take for a cheetah to speed up from 10.5 m/s to
12.2 m/s?
a. 0.28 s
c. 3.5 s
b. 1.7 s
d. 10 s
____ 20. The SI unit of force, named for the scientist who described the relationship between motion and force, is
called the
a. newton.
c. curie.
b. einstein.
d. pasteur.
____ 21. Acceleration can mean
a. speeding up.
b. slowing down.
c. changing direction
d. All of the above.
____ 22. The distance traveled by an object divided by the time it takes to travel that distance is called
a. average velocity.
c. average acceleration.
b. average speed.
d. activity.
____ 23. A motorist travels at an average speed of 55.0 mi/h for 4.25 h. How far did he travel?
a. 0.08 mi
c. 55 mi
b. 13 mi
d. 234 mi
____ 24. A runner finishes a 500.0 m race in 1.6 min. What is her average speed?
a. 0.19 m/s
c. 96 m/s
b. 5.2 m/s
d. 312 m/s
____ 25. A weightlifter presses a 400 N weight 0.5 m over his head in 2 seconds. What is the power of the
weightlifter?
a. 100 N
c. 400 watts
b. 25 watts
d. 100 watts
____ 26. Acceleration is defined as the change in velocity divided by
a. speed.
c. time.
b. final velocity.
d. distance.
____ 27. The law that states that for every action force there is an equal and opposite reaction force is
a. Newton’s first law of motion.
c. Newton’s third law of motion.
b. Newton’s second law of motion.
d. the law of conservation of momentum.
____ 28. What are the units of work?
a. J
b. Nm
c. kgm2/s2
d. All of the above
0BJECTIVES 7.0-7.3 STUDY GUIDE
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