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13. Two objects are released from the same height at the same time, 23. Newton’s third law of motion states that forces occur in matched
and one has twice the weight of the other. Ignoring air resistance, pairs that act in opposite directions between two diff erent bodies.
a. the heavier object hits the ground fi rst. Th is happens
b. the lighter object hits the ground fi rst. a. rarely.
c. they both hit at the same time. b. sometimes.
d. whichever hits first depends on the distance dropped. c. often but not always.

14. A ball rolling across the floor slows to a stop because d. every time two bodies interact.

a. there is a net force acting on it. 24. If you double the unbalanced force on an object of a given mass,
b. the force that started it moving wears out. the acceleration will be
c. the forces are balanced. a. doubled.
d. the net force equals zero. b. increased fourfold.

15. The basic difference between instantaneous and average speed is that c. increased by one-half.

a. instantaneous speed is always faster than average speed. d. increased by one-fourth.
b. average speed is for a total distance over a total time of trip. 25. If you double the mass of a cart while it is undergoing a constant
c. average speed is the sum of two instantaneous speeds, divided unbalanced force, the acceleration will be
by 2. a. doubled.
d. the final instantaneous speed is always the fastest speed. b. increased fourfold.

16. Does any change in the motion of an object result in an acceleration? c. one-half as much.
a. Yes. d. one-fourth as much.
b. No. 26. Doubling the distance between the center of an orbiting
c. It depends on the type of change. satellite and the center of Earth will result in what change in the
17. A measure of how fast your speed is changing as you travel to gravitational attraction of Earth for the satellite?
campus is a measure of a. One-half as much
a. velocity. b. One-fourth as much
b. average speed. c. Twice as much
c. acceleration. d. Four times as much

d. the difference between initial and fi nal speed. 27. If a ball swinging in a circle on a string is moved twice as fast, the
18. Considering the forces on the system of you and a bicycle as you force on the string will be
pedal the bike at a constant velocity in a horizontal straight line, a. twice as great.
a. the force you are exerting on the pedal is greater than the b. four times as great.
resisting forces. c. one-half as much.
b. all forces are in balance, with the net force equal to zero. d. one-fourth as much.
c. the resisting forces of air and tire friction are less than the 28. A ball is swinging in a circle on a string when the string length is
force you are exerting. doubled. At the same velocity, the force on the string will be
d. the resisting forces are greater than the force you are exerting. a. twice as great.
19. Newton’s first law of motion describes b. four times as great.

a. the tendency of a moving or stationary object to resist any c. one-half as much.
change in its state of motion. d. one-fourth as much.
b. a relationship between an applied force, the mass, and the 29. Suppose the mass of a moving scooter is doubled and its velocity

resulting change of motion that occurs from the force. is also doubled. The resulting momentum is
c. how forces always occur in matched pairs. a. halved.
d. none of the above. b. doubled.
20. You are standing freely on a motionless shuttle bus. When the c. quadrupled.
shuttle bus quickly begins to move forward, you d. the same.
a. are moved to the back of the shuttle bus as you move forward 30. Two identical moons are moving in identical circular paths, but
over the surface of Earth. one moon is moving twice as fast as the other. Compared to the
b. stay in one place over the surface of Earth as the shuttle bus slower moon, the centripetal force required to keep the faster
moves from under you. moon on the path is
c. move along with the shuttle bus. a. twice as much.
d. feel a force toward the side of the shuttle bus. b. one-half as much.
21. Mass is measured in kilograms, which is a measure of c. four times as much.
a. weight. d. one-fourth as much.
b. force. 31. Which undergoes a greater change of momentum, a golf ball or
c. inertia. the head of a golf club, when the ball is hit from a golf tee?
d. quantity of matter. a. The ball undergoes a greater change.

22. Which metric unit is used to express a measure of weight? b. Th e head of the club undergoes a greater change.
a. kg c. Both undergo the same change but in opposite directions.

b. J d. The answer depends on how fast the club is moved.
c. N
d. m/s 2

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