Download 1. The displacement of an object C) is a vector representing

1.
The displacement of an object
C) is a vector representing the change in the
position of an object.
2.
Average speed
A) is defined as total distance traveled divided
by total time.
3.
An object’s displacement divided by total time defines
an object's
A) average velocity.
4.
The combination of speed and direction defines an object's
C) velocity vector.
5.
A cyclist rides 10 miles in 45 minutes. During his ride,
he waited for a total of 3 minutes at two stoplights.
C) His average speed was 13.3 mph.
6.
A cyclist rides 15 miles in 45 minutes. During his ride,
he waits for a total of 5 minutes at two stoplights.
A) His average speed was 20 mph.
7.
A car drives east on College at 30 mph. A second car
drives east on Prince at 30 mph. Mark all of the correct
statements (there may be more than one):
A) The cars have the same speed.
B) The cars have the same direction.
C) The cars have the same velocity.
D) The cars have the same speeds, but different velocities.
8.
9.
A car drives east on College Avenue at 30 mph. A second car drives west on Prince Street at 30 mph. Mark
all of the correct statements (there may be more than
one):
A) The cars have the same speed.
B) The cars have the same direction.
C) The cars have the same velocity.
D) The cars have the same speed, but different
velocity.
On a car trip, you need to average 60 mph. Because of
heavy traffic and road construction, when you are exactly halfway to your destination, you notice that you
have only averaged 30 mph. To meet your goal of an
average speed of 60 mph, what should you do for the
rest of the trip?
D) Relax and enjoy the scenery; it does not
matter how fast you go, you won't be able to
meet your goal.
10. An Olympic sprinter runs 100 m in 9.6 seconds, for an
average speed of 10.4 m/s.
B) His speed must exceed 10.4 m/s for part of
the sprint.
11. Upon doing experiments with inclined planes, Galileo
concluded that
D) steeper inclines yield greater acceleration.
12. Which of the following units could not be used to express an acceleration?
B) m/s3
13. In 2.5 seconds, a car increases its velocity from 60 km/
h to 65 km/h. A bicycle goes from rest to 5 km/h in the
same 2.5 seconds. Which undergoes the greater acceleration?
D) Neither; the acceleration of both is 2 (km/
h)/s.
14. A car accelerates from rest. After 10 seconds, its speed
is 50 m/s. What was its acceleration?
B) 5 m/s2.
15. You are jogging on a circular track.
A) Your speed may be constant.
16. Mark each of the following correct statements (there
may be more than one).
A) Acceleration is the result of a change in
speed.
B) Acceleration is the result of a change in direction.
C) An object with constant speed can be accelerating.
D) An object traveling in a straight line can be
accelerating.
17. One of the statements below is incorrect. Mark the incorrect statement.
C) An object with constant speed can never be
accelerating.
18. An automobile with a velocity of 45 mph east experiences an acceleration of 5 mph/s west.
B) The car loses 5 mph of speed every second.
19. In the absence of air, freely falling objects
D) have the same constant, non-zero acceleration.
20. Mark each correct statement (there may be more than
one). You throw a baseball straight up in the air. At the
very top of its trajectory,
A) its velocity is zero.
B) its velocity is 9.8 m/s down.
C) its acceleration is zero.
D) its acceleration is g = 9.8 m/s2 down.
21. You "accidentally" drop a water balloon off the second
story balcony. It bursts on the pavement below exactly
1.25 seconds later.
B) The height of the balcony is 7.66 m.
22. The water balloon in the previous question strikes the
ground with a speed of:
C) 12.25 m/s.
23. You drop a golf ball from the third story landing of the
stairwell. It strikes the ground 1.40 s later.
C) The height of the stairwell is 9.60 m.
24. The golf ball in the previous question strikes the
ground with a speed of:
B) 13.7 m/s.
25. From the edge of the third story balcony, you throw one
tennis ball straight up with a speed of 30 m/s, and a
second ball straight down with a speed of 30 m/s. The
balls strike the ground below.
C) The balls each strike the ground with the
same velocity, though not at the same time.
36. In a vacuum tube, a penny and a feather are released
from rest.
A) The force of gravity on the penny is greater.
26. A boat in a river moves with a velocity of 10 km/h relative to the water. The current flows at 8 km/h. If the
boat heads directly upstream, its velocity relative to the
shore is
A) 2 km/h.
38. Two skydivers leap from a plane and pull their identical
parachutes at the same time.
A) The more massive diver initially experiences greater acceleration.
27. As you sit in the back seat of a moving car, you watch
the rain streak down the window. Although it's raining,
there is no wind. You estimate that the angle of the
streak is 45°.
B) The car is moving forward at the same
speed the rain is falling down.
28. A hockey puck slides across a perfectly frictionless ice
rink with a constant velocity.
A) The puck will continue to slide until an external force acts upon it.
29. On July 20, 1969, Neil Armstrong became the first man
to walk on the moon.
D) His mass remained the same on Earth, in
space, and on the moon.
30. You have 1 kg of feathers, and 1 kg of lead birdshot (is
that how you got the feathers?). Mark each correct
statement (there may be more than one).
A) The lead is more massive.
B) The feathers have less inertia.
C) The lead has greater density.
D) The feathers have more volume.
31. You must apply a horizontal force of 20 N to the left for
a 15 kg crate of books to move with a constant speed.
Mark each correct statement (there may be more than
one).
A) The crate's acceleration is zero.
B) The crate's acceleration is 1.33 m/s2.
C) Friction exerts a 20 N force to the right on
the crate.
D) Friction exerts a force, but you don't have enough
information to figure out how much.
32. A child weighing 400 N stands at rest with one foot on
each of two bathroom scales.
B) The readings on the scales add up to exactly
400 N.
33. Two objects (say a 0.1 kg homework paper and a 46 kg
Labrador retriever) are each in a state of rest.
D) The dog can increase his inertia by eating
the homework.
34. Which of the following is an example of a Newton #3
action-reaction pair?
B) The force of gravity on the earth due to the
sun and the force of gravity on the sun due
to the earth.
35. Two forces are acting on an object. The object is at rest.
C) The forces add up to zero, but are not an
action-reaction pair.
37. A book sits at rest on a table.
B) There are several forces acting on the book.
39. A train collides head-on with an unlucky horsefly.
D) The bug experiences a greater acceleration
than the train.