If an apple falls a distance of 2 meters in its first second of fall, then 2 meters in its next second of fall, and again 2 meters during its third second of fall, the acceleration of the apple is
1) 0 m/s2.
2) 2 m/s2.
3) 4 m/s2.
4) 10 m/s2.
5) actually, more than 10 m/s2.
This is because
6) no change in velocity occurs during fall.
7) the apple increases in distance by 2 meters for each successive second.
8) the average velocity is 1 m/s for each successive second.
9) its weight is counterbalanced by its inertia.
[Ques. 2] An object drops in free fall. At one instant it is moving at a speed of 50 meters per second. Exactly one second later its speed is about
1) 10 m/s.
2) 50 m/s.
3) 60 m/s.
4) 100 m/s.
This is because
5) no net force acts on the object while in its state of free fall.
6) it gains a speed of about 10 m/s for each second of fall.
7) its velocity nearly doubles each second.
[Ques. 3] The force required to maintain a body at constant velocity in free space is equal to
1) the mass of the body.
2) zero.
3) the weight of the body.
4) the force required to stop it.
5) none of these.
This is in accordance with the law of
6) inertia.
7) action/reaction.
8) gravitation.
9) energy conservation.
[Ques. 4] An object is dropped from a position of rest. At the end of the first second of free fall it will have traveled about
1) 0 m
2) 5 m
3) 10 m
and its velocity will be about
4) 0 m/s.
5) 5 m/s.
6) 10 m/s.
[Ques. 5] The property of objects to resist a change in motion is called
1) friction,
2) velocity,
3) inertia,
4) acceleration,
5) gravity,
and it is measured by its
6) speed.
7) velocity.
8) mass.
9) all of these.
[Ques. 6] A rifle is fired straight downward from a high-altitude balloon. If the bullet leaves the barrel at 100 m/s, then its speed one second later (neglecting air resistance) will be about
1) 10 m/s
2) 100 m/s
3) 105 m/s
4) 110 m/s
and its distance below will be about
5) 5 m.
6) 100 m.
7) 105 m.
8) 110 m.
9) 120 m.
[Ques. 7] An object is accelerating if it moves
1) with constant velocity
2) in a circular path
3) in a straight-line path
because it is undergoing a change in its
4) speed.
5) direction.
6) net force.
[Ques. 8] A car increases its speed from 60 to 65 miles per hour in the same time that a bicycle increases its speed from rest to 5 miles per hour. Acceleration is
1) greater for the car,
2) greater for the bicycle,
3) the same for each,
principally because
4) the car undergoes the greater change in velocity.
5) the bicycle has considerably less mass.
6) both undergo equal increases in velocity during the same interval of time.
[Ques. 9] Neglecting friction, a ball rolling along a horizontal plane will
1) accelerate indefinitely.
2) roll until the force used to roll it was used up.
3) roll indefinitely at a constant speed.
This illustrates
4) the basic principle that a body requires a push or pull to keep it moving.
5) inertia.
6) the law of net force.
[Ques. 10] To say that an object is moving at constant velocity means that it is
1) at rest,
2) moving at an unchanging speed,
3) moving at an unchanging speed in a straight-line path,
and that its acceleration is
4) zero.
5) constantly increasing (or decreasing).
6) uniform.
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