INSTRUCTIONS
1. The average acceleration of an object is defined to be the
a. distance it travels divided by the time it takes.
---> b. change in its velocity divided by the time this change takes.
c. change in its speed divided by the time this change takes.
d. average of the accelerations during the two halves of the trip.
2. An object is accelerating
a. only when its speed changes.
b. only when its direction changes.
c. only if either its speed or direction changes.
---> d. if its speed or direction, or both, change
3. Suppose that you look out a tenth-floor window and see a ball
falling at 20 m/s. How fast will this ball be falling 2 s later?
a. 15 m/s
b. 25 m/s
---> c. 40 m/s
d. 45 m/s
4. A baseball is thrown vertically upward with a speed of 40 m/s.
How long does it take to get to the top of its path?
a. 1 s
b. 2 s
c. 3 s
---> d. 4 s
5. If the net force on a hot-air balloon is directed straight
upward, which way does the acceleration point?
a. downward
---> b. upward
c. upward only if the balloon is rising
d. the same direction as the force of gravity
6. Assume that you are driving down a straight road at constant speed.
A small ball is tied on the end of a string hanging from the rear
view mirror. Which way will the ball swing when you apply
the brakes?
---> a. forward
b. backward
c. It will not swing
d. the same direction a lighter-than-air baloon would swing
7. A Vanderbilt basketball player has an instantaneous velocity
of 4 m/s as she races towards the UT basket. At that same
instant, a team mate scores. She immediately slows down and
follows a straight line path directly between both
goal posts with a constant acceleration of -2 m/s/s.
What will be her velocity and position 4 seconds later?
a. 4 m/s towards UT basket, 4 m closer to Vandy basket
b. 4 m/s towards UT basket, back to her original position
---> c. 4 m/s towards Vandy basket, back to her original position
d. 8 m/s towards UT basket, 4 m closer to U of T basket
8. If the mass and weight of an astronaut are measured on the earth and
on the moon, we will find that the masses are .... and the weights
are ....
a. the same ... the same
b. different ... different
---> c. the same ... different
d. different ... the same
9. A ball falling from a great height will reach terminal speed when
its .... goes to zero.
a. inertia
---> b. net force
c. weight
d. speed
10. What is the net force on an 80-kg ice skater with a constant
velocity of 6 km/hour east?
---> a. zero
b. 800 N
c. 80 N
d. 480 N
11. Two skaters face each other on perfectly smooth ice. One skater
weighs twice as much as the other. Assuming that the bigger skater
pushes the smaller, which of the following statements is true?
a. The bigger skater won't move.
---> b. The bigger skater will move with the smaller acceleration.
c. The bigger skater will move with the larger acceleration.
d. Both skaters move with the same acceleration.
12. In uniform circular motion the
a. acceleration is parallel (or antiparallel) to the velocity.
---> b. acceleration is perpendicular to the velocity.
c. acceleration is vertical, while the velocity can be in any direction.
d. acceleration is vertical and the velocity is horizontal.
13. A car drives off a vertical cliff at a speed of 24 m/s. If it takes
3.0 s for the car to hit the ground, how far from the base of the
cliff does it land? (Ignore air resistance.)
a. 48 m
b. 8 m
c. 24 m
---> d. 72 m
14. Newton's first law for rotational motion states that an object will
maintain its state of rotational motion unless acted on by an
unbalanced (or net)
a. force
b. velocity
c. inertia
---> d. torque.
15. A ball bouncing straight up and down with no air resistance has
---> a. a constant downward acceleration equal to 9.8 m/s/s
b. a changing acceleration that depends on the ball's direction
c. a downward acceleration which decreases as the bounces subside
d. a constant velocity
(Hint: what is the net force on the ball and what does this
imply about the acceleration from Newton's second law? )
16. Two students standing in place and pulling with equal forces of
about 100 lbs in opposite directions on a spring attached to a scale
demonstrates
a. the net force on the spring is 100 lbs, the scale reads 100 lbs
---> b. the net force on the spring is zero, the scale reads 100 lbs
c. the net force on the spring is 200 lbs, the scale reads 100 lbs
d. the net force on the spring is zero, the scale reads 200 lbs
17. What acceleration is produced by a force of 100 N acting on a mass
of 10 kg if its velocity is 20 m/s and the frictional force is 30 N?
a. 10 m/s/s
b. 9 m/s/s
c. 8 m/s/s
---> d. 7 m/s/s
18. The trajectory of a golf ball, neglecting air resistance, has
---> a. a constant downward acceleration and a constant horizontal speed
b. a constant increasing downward acceleration and a constant
horizontal speed
c. an decreasing acceleration upwards and increasing acceleration
downward with a constant horizontal speed
d. a contant downward acceleration and a decreasing horizontal speed.
19. The motion of a block sliding down a frictionless ramp can
be described as motion with
a. a uniformly increasing speed.
b. a constant acceleration less than 10 m/s/s.
c. a changing velocity.
---> d. all of the above
20. An olympic high diver jumping off the 10 meter platform
executing a spinning dive will hit the water after how
many seconds (neglect air resistance)
a. 2 seconds
---> b. 1.4 seconds
c. less than 1.4 seconds depending on their rate of spin
d. more than 1.4 seconds depending on their rate of spin
21. A ball with a mass of 0.5 kg is thrown vertically
upward with a speed of 25 m/s. What are its speed and direction
two seconds later?
a. 10 m/s upward
---> b. 5 m/s upward
c. zero
d. 5 m/s downward
22. Which of the following is the third-law force that accompanies the
force that an apple exerts on a tree? It is the force that the
a. earth exerts on the apple.
b. apple exerts on the earth.
---> c. tree exerts on the apple.
d. air exerts on the apple.
23. The same net force is applied to object A and object B.
The observed accelerations of the two objects are not the same;
object A has an acceleration one-third that of object B.
Which of the following is correct?
---> a. Object A has three times the mass of object B.
b. Object A has one-third the mass of object B.
c. Object A has a different, less streamlined shape than object B.
d. Object A has more friction than object B.
24. A 40-N crate is being pushed across a horizontal floor.
If the coefficient of sliding friction is 0.5, what is the
frictional force acting on the crate?
---> a. 20 N
b. 40 N
c. 100 N
d. 160 N
25. If F1 is the force exerted on a cart by a horse and F2 is the
force exerted on the horse by the cart, then
a. F1 is greater than F2 if the cart is accelerating
b. F2 is greater than F1 if the cart is accelerating
---> c. F1 is equal to F2
d. all of the above are possible
26. A baseball player throws a ball from left field toward home
plate. Assume that you can neglect the effects of air resistance.
At the instant the ball reaches its highest point, what is the
direction of the ball's acceleration? (ignore air resistance)
a. up
---> b. down
c. in the direction of the ball's velocity
d. the acceleration is zero
27. In uniform circular motion the OMIT
a. acceleration is parallel (or antiparallel) to the velocity.
b. acceleration is perpendicular to the velocity.
c. acceleration is vertical, while the velocity can be in any direction.
d. acceleration is vertical and the velocity is horizontal.
28. Sharon has a mass of 60 kg and is standing on a giant
skateboard that is initially at rest and has a mass of 60 kg.
If we ignore frictional effects with the floor, what is the speed of
the skateboard if Sharon walks to the right with a speed of 3 m/s?
a. 1 m/s
---> b. 3 m/s
c. 6 m/s
d. zero
29. An astronaut "floating" in Skylab has an initial rotational
motion but no initial translational motion relative to Skylab.
a. She continues to rotate because she experiences no net torque.
b. She continues to rotate because the net force influences
only her center of mass motion.
c. She is weighless as she falls toward Earth
---> d. All of the above
30. You will be able to pull a tablecloth from a table without
crashing the chinaware to the floor if what conditions are
met?
a. You make sure the cloth and the dishes are smooth and then
you move the tablecloth slow enough to not cause damage.
---> b. You minimize the frictional force between the dishes and
the tablecloth and you jerk the cloth as rapidly as
possible keeping it level with the tabletop.
c. This is a difficult to perform trick that requires creating
an illusion.
d. All the above are true.
31. What is the magnitude of the net force when a force of 3 N
combines with a force of 4 N acting at a right angle with
respect to each other?
a. 1 N
b. 7 N
---> c. 5 N
d. 25 N
32. A physics student reports that upon arrival on planet X, he promptly
sets up the "monkey-shoot" demonstration. If the gravity on planet X
is twice what it is on earth, he should obtain a
a. miss since the monkey's weight is twice as big now.
b. hit only if the ball's horizontal velocity is increased.
c. miss since the monkey's mass is unchanged.
---> d. hit since the ball and the monkey fall vertically at the
same rate.
33. Gary reads about Newton's third law while sitting in a room
with a single closed door. He reasons that if he applies
a force to the door there will be an equal and opposite force
that will cancel his pull and he never will be able
to escape. What is wrong with Gary's reasoning?
a. He hasn't applied Newton's third law correctly.
b. The force on the door must be greater than the force
of the door on him.
---> c. The motion of the door is affected only by the net forces
on the door, and the reaction force on him is irrelevant.
d. All of he above.