Physics Exam 3 Tested Questions and
Accurate Answers (Latest version).
Complete each statement about the sign of the work done on a baseball.
1. Carlton catches a baseball and his hand moves backward as he brings the ball to a halt, doing
... work on the ball
2. Carlton throws a baseball, doing ... work on the ball
3. Carlton carries a baseball in his hand as he rides his bicycle in a straight line at constant
speed, doing ... work on the ball
4. Carlton carries a baseball in his hand as he rides his bicycle in a straight line with increasing
speed, doing ... work on the ball
1. negative
2. positive
3. zero
4. positive
Kendra separately pushes two boxes in a straight line at constant velocity over the same
distance on level ground. Each box begins and ends at rest. Kendra exerts no force to stop either
box; friction brings them both to rest. The contact surfaces and areas between each box and the
floor are the same for both, but one box is heavy and the other is light.
Which statement is correct?
A. Kendra does more work on the heavy box, but the net work done on both boxes is equal.
B. Kendra does the same amount of work on both boxes, and the same amount of net work is
also done on both boxes.
C. Kendra does the same amount of work on both boxes, but more net work is done on the
heavy box.
D. Kendra does more work on the light box, but more net work is done on the heavy box.
,E. Kendra does more work on the heavy box, and more net work is also done on the heavy box.
A. Kendra does more work on the heavy box, but the net work done on both boxes is equal.
Three objects of the same mass begin their motion at the same height. One object falls straight
down, one slides down a low-friction inclined plane, and one swings in a circular arc on the end
of a string. All three objects end at the same height.
On which object does gravity do the most work?
A. The gravity does equal work on all three objects
B. the object traversing the circular arc
C. the object sliding down the low-friction incline
D. the object in free fall
A. The gravity does equal work on all three objects
A box sits on the horizontal bed of a truck that is accelerating to the left, as shown in the
diagram. Static friction between the box and the truck keeps the box from sliding around as the
truck accelerates.
The work done on the box by the static friction force as the accelerating truck moves a distance
𝐷 to the left is
A. negative.
B. zero.
C. dependent upon the speed of the truck.
D. positive.
D. positive.
, A hockey player does work on a hockey puck in order to propel it from rest across the ice (which
is assumed to be frictionless). When a constant force is applied over a certain distance, the puck
leaves his stick at a speed 𝑣.
If instead he wants the puck to leave at speed 2𝑣, by what factor must he increase the distance
over which he applies the same force?
A. 2
B. √2
C. 8
D. 4
E. 2√2
D. 4
If force is in the direction of motion, work is ....
positive
If force is in the opposite direction of motion, work is ....
negative
A box attached at rest to a spring at its equilibrium length. You now push the box with your
hand so that the spring is compressed a distance D, and you hold the box at rest in this new
location. During this motion, the spring does ...
A. Positive work
B. Negative work
C. Zero work
Accurate Answers (Latest version).
Complete each statement about the sign of the work done on a baseball.
1. Carlton catches a baseball and his hand moves backward as he brings the ball to a halt, doing
... work on the ball
2. Carlton throws a baseball, doing ... work on the ball
3. Carlton carries a baseball in his hand as he rides his bicycle in a straight line at constant
speed, doing ... work on the ball
4. Carlton carries a baseball in his hand as he rides his bicycle in a straight line with increasing
speed, doing ... work on the ball
1. negative
2. positive
3. zero
4. positive
Kendra separately pushes two boxes in a straight line at constant velocity over the same
distance on level ground. Each box begins and ends at rest. Kendra exerts no force to stop either
box; friction brings them both to rest. The contact surfaces and areas between each box and the
floor are the same for both, but one box is heavy and the other is light.
Which statement is correct?
A. Kendra does more work on the heavy box, but the net work done on both boxes is equal.
B. Kendra does the same amount of work on both boxes, and the same amount of net work is
also done on both boxes.
C. Kendra does the same amount of work on both boxes, but more net work is done on the
heavy box.
D. Kendra does more work on the light box, but more net work is done on the heavy box.
,E. Kendra does more work on the heavy box, and more net work is also done on the heavy box.
A. Kendra does more work on the heavy box, but the net work done on both boxes is equal.
Three objects of the same mass begin their motion at the same height. One object falls straight
down, one slides down a low-friction inclined plane, and one swings in a circular arc on the end
of a string. All three objects end at the same height.
On which object does gravity do the most work?
A. The gravity does equal work on all three objects
B. the object traversing the circular arc
C. the object sliding down the low-friction incline
D. the object in free fall
A. The gravity does equal work on all three objects
A box sits on the horizontal bed of a truck that is accelerating to the left, as shown in the
diagram. Static friction between the box and the truck keeps the box from sliding around as the
truck accelerates.
The work done on the box by the static friction force as the accelerating truck moves a distance
𝐷 to the left is
A. negative.
B. zero.
C. dependent upon the speed of the truck.
D. positive.
D. positive.
, A hockey player does work on a hockey puck in order to propel it from rest across the ice (which
is assumed to be frictionless). When a constant force is applied over a certain distance, the puck
leaves his stick at a speed 𝑣.
If instead he wants the puck to leave at speed 2𝑣, by what factor must he increase the distance
over which he applies the same force?
A. 2
B. √2
C. 8
D. 4
E. 2√2
D. 4
If force is in the direction of motion, work is ....
positive
If force is in the opposite direction of motion, work is ....
negative
A box attached at rest to a spring at its equilibrium length. You now push the box with your
hand so that the spring is compressed a distance D, and you hold the box at rest in this new
location. During this motion, the spring does ...
A. Positive work
B. Negative work
C. Zero work
