ame: ________________________ Class: ___________________ Date: __________
ID: A
Exam 2--PHYS 101---F12--Ch 3, 4, & 5a
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. A person walks 20.0 meters to the west and 30.0 meters at an angle of 30.0° north of west. What is the
magnitude of the person’s displacement?
a.
b.
____
16.2 m
46.0 m
c.
d.
61.0 m
48.4 m
2. Consider these vectors. Which of these represents the vector for B-A ?
a.
b.
c.
.
d.
1
ame: ________________________
____
3. A vector has negative x and y-components. The y-component is bigger than the x-component. Which of
these is the only appropriate angle, measured from the +x axis, for this vector?
a.
b.
c.
____
d.
e.
230°
290°
0.5 s
1.0 s
1.5 s
d.
e.
2.0 s
2.5 s
5. Which of these statements is true for the object in projectile motion?
a.
b.
c.
____
190°
125°
350°
4. You kick a soccer ball with an initial velocity of 20.0 m/s at an angle of 30.° from the horizontal. It lands
some distance away. How long does it take to come back to the ground?
a.
b.
c.
____
ID: A
the y-component of the velocity doesn’t
change
the acceleration in the y-direction is
constant
the acceleration in the y-direction is zero
d.
e.
the maximum height is dependent on the
x-component of the velocity
the velocity of the object at the top of the
trajectory is zero
6. A student adds two vectors with magnitudes of 200 and 40. Which one of the following is the only possible
choice for the magnitude of the resultant?
a. 200
c. 260
b.
40
d. 100
2
ame: ________________________
____
7. A ball is rolled horizontally off a table with an initial speed of 0.24 m/s. A stopwatch measures the ball's
trajectory time from table to the floor to be 0.30 s. What is the height of the table?
a.
b.
____
0.44 m
0.22 m
c.
d.
0.33 m
0.11 m
8. A cart is accelerating along a flat surface. A cannon on the cart fires a ball directly overhead. Where does
the ball land when it comes back down?
a.
b.
____
ID: A
behind the cart
in front of the cart
c.
d.
in the cart
it depends on the speed of the cart at the
time of firing
9. This figure shows the trajectories of 3 punts, each of which has the same initial velocity. For which punt is
the football in the air for the longest amount of time?
a.
b.
A
B
c.
d.
C
All the same
____ 10. If we know an object is moving at constant velocity, we may assume:
a. the object is accelerating.
c. there are no forces acting on the object.
b. the object is losing mass.
d. the net force acting on the object is zero.
3
ame: ________________________
ID: A
____ 11. Which of these ideas was proposed by Aristotle?
a. The natural condition for a moving
c.
object is to remain in motion.
b. For every action there is an equal but
d.
opposite reaction.
The natural condition for a moving
object is to come to rest.
An object's acceleration is inversely
proportional to its mass.
____ 12. Two ropes are attached to a 40-kg object. The first rope applies a force of 25 N and the second, 40 N in the
opposite direction. What is the resultant acceleration of the object?
a.
b.
c.
d.
e.
1.6 m/s2
2.7 m/s2
1.0 m/s2
0.63 m/s2
0.38 m/s2
____ 13. A worker pulls a 200-N packing crate at constant velocity across a rough floor by exerting a force F = 55.0 N
at an angle of 35.0° above the horizontal. What is the coefficient of kinetic friction of the floor? (Hint:
F ≠ 200 !)
a.
b.
0.200
0.267
c.
d.
4
0.400
0.133
ame: ________________________
ID: A
____ 14. A 50 kg woman dangles a 50 kg mass from the end of a rope over the edge of a cliff. What is the tension in
the rope (the woman and mass are stationary).
a.
b.
250 N
0N
c.
d.
500 N
1000 N
____ 15. (MCAT) A man dangles a 10 kg mass from the end of a rope. If he steps on an elevator while still holding
the rope, and the elevator accelerates downward at 3 m/s 2, the tension in the rope will be
a.
b.
c.
130 N
30 N
100 N
d.
e.
0N
70 N
____ 16. A block of mass m rests on the floor of an elevator that is accelerating downward at 2 m/s 2. What is the
relationship between the force due to gravity (mg) and the normal force (N) on the block?
a. N=mg
d. N>mg
b. N<mg
e. depends on the speed of the elevator
c. N=0
5
ame: ________________________
ID: A
____ 17. This figure shows an inclined plane with a block; the block is accelerating up the inclined
plane. The 3 forces--normal force, weight, and an applied force ä
F --are labeled. Which of the following is
an appropriate equation that follows from the application of Newton’s second law of motion?
a.
b.
c.
ä
F − ä
F w sin60 o = ma y
ä
F = ä
Fw
ä
ä
F − F cos 60 o = 0
d.
ä
F + ä
F =ä
Fw
e.
all of these are correct
w
____ 18. You push an object along a rough surface. Which of these best describes the work done by the frictional
force?
a.
b.
positive
negative
c.
zero
____ 19. You push a grocery cart with a force of 12 N at an angle of 60° downward from the horizontal. How much
work do you do if you push the cart 6.0 meters?
a.
b.
72 J
36 J
c.
d.
6
6.0 J
62 J
ame: ________________________
ID: A
____ 20. This figure shows 4 blocks, each of which are moving to the right. For which block is the force F doing the
most negative work? (Each force has the same magnitude.)
a.
b.
a
b
c.
d.
c
d
____ 21. An 2.0 kg object is initially at rest. I push on with a force of 12 N over a distance of 3.0 m. What is the
velocity of the object?
a.
b.
6.0 m/s
8.0 m/s
c.
d.
36 m/s
72 m/s
____ 22. Dr. Young thinks his students are ___________________________! (Hint: The answer is not B, C, or D.)
a.
b.
the best ever
just so-so
____ 23. You are using version A of this exam.
a. A
b. B
c.
d.
not so good
horrible
c.
d.
C
D
7
ID: A
Exam 2--PHYS 101---F12--Ch 3, 4, & 5a
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
CT
D
B
D
D
B
A
A
A
A
D
C
E
B
C
E
B
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
A
B
B
B
A
A
A
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
DIF: 2
DIF: 2
1