Name: ________________________ Class: ___________________ Date: __________
ID: A
Exam 3 -- PHYS 101
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
____
____
____
____
1. A tire is mounted on a balancing machine. It is initially at rest. It begins to rotate, and, in 5.0 seconds, the
tire moves through 3.0 revolutions. In radians/second 2, what is its angular acceleration?
c. 0.6 rad /s2
a. 3.8 rad/s2
2
b. 1.5 rad/s
d. 0.75 rad/s 2
2. A merry-go-round moves through 3.5 revolutions. What is this angular displacement in units of degrees?
a. 1300°
c. 22°
b. 210°
d. 11°
3. A ball has a mass of 1.0 kg and is twirled in a circle horizontally on a string; the circular path has a radius of
3.0 m. It moves at a constant velocity. In 2.5 seconds, the ball moves through an angular displacement of 12
radians. What is the tension in the string?
a. 0.0048 N
c. 69 N
b. 72 N
d. 1.6 N
4. A merry-go-round, with a radius of 2 m, has an angular acceleration of 10 rad/s 2. What is the tangential
acceleration of a boy on the edge of the merry-go-round?
c. 2 m/s2
a. 20 m/s2
b. 5 m/s2
d. 20 rad/s2
5. Bonnie sits on the outer rim of a merry-go-round. Klyde sits midway between the center and the rim. The
merry-go-round makes one revolution every two seconds. Who has the larger centripetal acceleration?
a. centripetal acceleration is the same for
c. Klyde
both
b. both the same
d. Bonnie
6. An object at rest begins to rotate with a constant angular acceleration. If the object rotates through an angle θ
in the time t, through what angle did it rotate in the time t.
1
1
c. 2 θ
a. 9 θ
b.
1
3
θ
d.
1
1
4
θ
Name: ________________________
____
____
ID: A
7. A potter’s wheel moves from rest to an angular speed of 6 rad/s in 30 seconds. What is its angular
acceleration?
c. 5 rad/s2
a. 0.2 rad/s2
b. 2700 rad/s 2
d. 180 rad/s2
8. A wheel spins at a constant velocity in the clockwise direction and moves through 100 radians in 10 seconds.
What is its angular velocity?
a. 1000 rad/s
c. -10 rad/s
b. -1000 rad/s
d. 10 rad/s
____ 9. Klyde sits on the outer rim of a merry-go-round with a radius of 2 meters, and Bonnie sits midway between
the center and rim. The merry-go-round makes one complete revolution every 2 seconds. What is the angular
velocity, in revolutions/second, of Klyde?
a. 4 rev/s
c. 2 rev/s
b. 0.5 rev/s
d. 1 rev/s
____ 10. What is the unit for torque?
c. N/m
a. kg m/s2
b. N
d. N•m
____ 11.
In this figure, Lisa sits on a see-saw 2 meters from the pivot point. Lisa has a mass of 50 kg. If Bob has a
mass of 80 kg, what distance must he be from the pivot point for the see-saw to balance (i.e. be in
equilibrium)?
a.
b.
3.1 m
2.0 m
c.
d.
2
1.3 m
1.8 m
Name: ________________________
ID: A
____ 12. In this figure, four balls of different masses are connected by massless, rigid bars. Each of the bars has a
length of 1m. What is the moment of inertia for this system if it rotates about an axis that is perpendicular to
the page and through ball #2?
a.
b.
0.75 kg m2
1.0 kg m2
c.
d.
3
0.25 kg m2
0.50 kg m2
Name: ________________________
ID: A
____ 13. This figure shows the human arm. The forearm rotates about the elbow (point O), and the biceps exerts a
force on the ulna at 0.03 m from the elbow. The total length of the forearm and hand is 0.35 m. What force
must the biceps exert in order for this arm to hold the bowling ball (whose weight is 50. N) steady (i.e. in
equilibrium)?
a. 18 N
c. 50 N
b. 580 N
d. 220 N
____ 14. A thin hoop is rolling with an angular velocity of 11 radians per second. It has a radius of 1.2 meter and a
mass of 5.0 kg. What amount of work is required to stop the hoop?
a.
b.
-440 J
-220 J
c.
d.
4
66 J
-300 J
Name: ________________________
ID: A
____ 15. This figure represents a solid disk whose mass is 10 kg and radius (r B) is 1 meter. As shown in the figure,
two forces are applied to the disk: F A has a magnitude of 50 N and is applied at a radius equal to 0.5 m (r A).
FB has a magnitude of 50 N and is applied at a radius equal to 1.0 m (r B); this force is at an angle of 30° from
the tangent of the circle. What is the net torque on the wheel?
____ 16.
____ 17.
____ 18.
____ 19.
a. 18 N•m
c. 68 N•m
b. -25 N•m
d. -18 N•m
When a tape is played on a cassette deck, there is a tension in the tape that applies a torque to the supply reel.
Assuming the tension remains constant during playback, how does this applied torque (i.e. the torque on the
supply wheel) vary as the supply reel becomes empty?
a. not enough information given
c. remains constant
b. increases
d. decreases
You have two disks. The first has twice the mass of the second disk. The second disk has twice the radius of
the first disk. Which has the larger moment of inertia?
a. both have the same moment of inertia
c. second disk
b. first disk
d. not enough information given
Which of these is not a state of matter?
a. liquid
c. gas
b. solid
d. cold
Which of the following states of matter makes up most of the matter in the universe?
a. gas
d. dark matter
b. plasma
e. solid
c. liquid
5
Name: ________________________
ID: A
____ 20. The density of navy beans is 800 kg/m3. What is the specific gravity of navy beans?
a. 0.8
c. 8
b. 1.25
d. 0.08
____ 21. The apparent weight of an object submerged in a liquid is equal to its actual weight minus the buoyant force.
What is the apparent weight of a solid PVC sphere with a volume of 1.2 m 3 and density of 1300 kg/m3 when
it is submerged in water, whose density is 1000 kg/m 3?
a.
b.
3500 N
1600 N
c.
d.
12000 N
15000 N
f = 10 N, a=1 cm2, and A=10 cm2. What is ä
F?
____ 22. In this figure, ä
a.
b.
10 N
1N
c.
d.
6
0.1 N
100 N
Name: ________________________
ID: A
____ 23.
This figure shows an air bubble at a depth of 4 m in water ( ρ = 1000 kg/m3). If the pressure above the water
is 1.3 atmospheres, what is the pressure within the bubble? (1 atm= 1 × 10 5 N/m2)
a. 5.2×108 N/m2
c. 1.7×105 Pa
b. 1.4 atm
d. 3.9×104 atm
____ 24. This figure shows a barometer. If the barometer is filled with water ( ρ=1000 kg/m3), what is the height when
the pressure P 0=1.7 atmosphere? (1 atm=1×105 N/m2)
a.
b.
17 m
0.17 mm
c.
d.
7
10 m
760 mm
Name: ________________________
ID: A
____ 25. A mountain climber has a mass of 100 kg. He has a rope whose unstretched length is 100 m; the
cross-sectional area of the rope is 8×10-5 m2. When the rope supports the total weight of the mountain
climber, the rope stretches by 2 m. Assume the cross-sectional area does not change. What is the Young’s
modulus for the rope?
a. none of these
c. 6×107 N/m2
8
2
b. 6×10 N/m
d. 6 N/m2
____ 26. Which of these is not a requirement for an ideal gas:
a. incompressible
c. irrotational
b. viscous
d. steady motion
____ 27. When you partially close the end of a garden hose, the velocity of the water increases. This is an application
of which principle or equation:
a. Pascal’s Principle
c. Bernoulli’s Equation
b. Archimede’s Principle
d. Equation of Continuity
____ 28. Water flows through 2 sections of pipe as shown in this figure. In the first section, the pressure is P 1=3.0×105
Pa, and the velocity is v 1=3.0 m/s. The cross sectional area of the first pipe is 0.50 m 2. In the second section
of pipe, the velocity is 6.0 m/s and the cross-sectional area is 0.25 m 2. What is the pressure, P 2, in the second
section of pipe?
a. 1.2 atm
c. 3.1×105 Pa
b. 2.9×105 Pa
d. none of these
____ 29. You are using Version A of this test. Please answer “A” for this question and write “Version A” on your
scantron sheet.
a. A
c. C
b. B
d. D
8
Name: ________________________
ID: A
____ 30.
a.
1
b.
9
1
ID: A
Exam 3 -- PHYS 101
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.
24.
25.
26.
27.
28.
29.
30.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
B
A
C
A
D
A
A
C
B
D
C
D
B
A
D
D
C
D
D
A
A
D
C
A
B
B
D
B
A
B
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
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
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1