Name: ________________________ Class: ___________________ Date: __________
Exam 4--PHYS 101--F14
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. A wheel, initially at rest, rotates with a constant
acceleration of 2.0 rad/s 2. What is the time interval
required for it to reach a 16-rad displacement after
starting from rest?
4. One revolution is the same as
a. 57 rad
b.
c.
d.
e.
a.
b.
c.
d.
2
π rad
1 rad
2π rad
5. What is the angular velocity of the second hand of
a clock?
16 s
4.0 s
8.0 s
2.8 s
a.
b.
c.
d.
2. A potter's wheel moves from rest to an angular
speed of 8.0 rev/s in 2.0 s. Find its angular
acceleration in rev/s 2.
a.
b.
c.
d.
π rad
1 rad/s
2 rad/s
0.5 rad/s
0.1 rad/s
6. If a wheel turns with constant angular speed then:
a. the angle through which the wheel turns in
each second increases as time goes on
b. the angle through which the wheel turns in
each second decreases as time goes on
c. each point on its rim moves with constant
acceleration
d. the wheel turns through equal angles in equal
times
e. each point on its rim moves with constant
velocity
16 rev/s2
8.0 rev/s2
4 rev/s2
0.25 rev/s2
7. An object at rest begins to rotate with a constant
angular acceleration. If this object has an angular
velocity of ω in time t, what is its angular velocity
3. Which of these is a measure of angular
displacement?
I. radians
II. degrees
III. revolutions
IV. arcs
a. I alone
b. I & II
c. I, II, and III
d. III & IV
after time
a.
b.
c.
d.
e.
1
0
2ω
ω/4
4ω
ω/2
1
2
t?
12. The following figure shows a configuration of
particles arranged on an equilateral triangle, whose
sides are all 4.0 m. The rotation axis is the dashed
line in this figure. What is the moment of inertia
for this configuration of particles?
8. A particle moves in a circular path of radius 0.10 m
with a constant angular speed of 5 rev/s. The
acceleration of the particle is:
a.
b.
c.
d.
e.
500π m/s2
1000π2 m/s2
0.10π m/s2
0.5 m/s2
10π2 m/s2
9. What is the moment of inertia for a hula-hoop with
a mass of 1kg and a diameter of 1m?
a.
b.
c.
d.
0.25 kgm²
0.50 kgm²
2 kgm²
1 kgm²
a.
b.
c.
d.
10. A 1 500-kg car rounds an unbanked curve with a
radius of 52 m at a speed of 12 m/s. What
minimum coefficient of friction must exist between
the road and tires to prevent the car from slipping?
a.
b.
c.
d.
13. Consider this figure of a rod rotating about the axis
labeled “C.” What is the net torque?
0.18
0.30
0.28
0.37
a.
b.
c.
d.
11. Consider this bar that can rotate about points A, B,
and C. About which point, does the bar exhibit the
greater moment of inertia?
a.
b.
c.
d.
e.
48 kg m2
72 kg m2
96 kg m2
24 kg m2
30 Nm counter clockwise
0 Nm
40 Nm counter clockwise
60 Nm counter clockwise
14. Consider the rod in the previous question. The rod
has a mass of 3 kg. After 2 seconds of the torque
acting on the rod, what is the rod’s angular
velocity?
a.
b.
c.
d.
A
B
C
A&C
they are all the same moment of inertia
2
30 rad/s
60 rad/s
45 rad/s
15 rad/s
15. A bar has a moment of inertia of 2 kg m2 and is
rotating at 3 rev/s. It engages with a flywheel,
which is stationary and has a moment of inertia of
4 kg m2. After they engage, both move at the same
speed. What is this new speed?
a.
b.
c.
d.
e.
19. This figure shows a hydraulic lift. The force F 1 has
a magnitude of 100 N, and the area A 1 is 0.01 m2.
If the area A2 is 1.0 m2, what is the weight of the
truck?
1 rev/s
1.5 rev/s
3 rev/s
9 rev/s
4.5 rev/s
16. A figure skater is rotating at 5 rev/s. Then, she
moves her arms out and is then rotating at 10 rev/s.
Which of these statements is true?
a. she has increased her moment of inertia by a
factor of 2
b. she has decreased her moment of inertia by a
factor of 2
c. her moment of inertia is the same; she has just
sped up
d. she has increased her moment of inertia by a
factor of 4
e. she has decreased her moment of inertia by a
factor of 4
a.
b.
c.
d.
20. Pascal’s principle says:
a. the buoyant force equals the weight of the
displaced fluid
b. a change in pressure at one point in an
incompressible fluid is felt at every other point
in the fluid
c. energy is conserved in a flowing ideal fluid
d. a small input force always causes a large output
force
17. Which of these is considered a fluid:
I. Solid
II. Liquid
III. Gas
a. II only
b. I, II, and III
c. II & III
d. III only
21. A tendon in your arm, without any pressure on it,
has a length of 0.10 m. The cross sectional area is
0.75 cm2 (=7.5×10-5 m2) By how much does it
stretch (in cm) when a force of 100 N is applied to
it? (The Young’s modulus for a tendon is 2×107 Pa)
18. How many cubic meters of water are in 300 kg of
water?
a.
b.
c.
d.
e.
100,000 N
10,000 N
1,000,000 N
1000 N
0.3 m3
3 m3
30 m3
300 m3
3000 m3
a.
b.
c.
d.
3
7.5 cm
0.7 cm
0.4 cm
1.3 cm
26. Consider this manometer. Which statement best
describes the relationship between P and P 0?
22. This figure shows a barometer. If the barometer is
filled with water, what is the height when the
pressure P=0.2 atmosphere?
a.
b.
c.
d.
a.
b.
c.
d.
760 mm
17 m
2.0 m
10 m
27. Water flows through a pipe at 3.0 m/s with a
cross-sectional area of 0.5 m 2. The pipe grows
wider to 1.0 m2. What is the speed of the water in
the larger pipe?
23. A blood platelet drifts along with the flow of blood
through an artery that is partially blocked. As the
platelet moves from the wide region into the
narrow region, the blood pressure:
a. increases
b. decreases
c. stays the same
24. The continuity equation is based on which of these
laws:
a. Conservation of Energy
b. Archimede’s Law
c. Conservation of Matter
d. Conservation of Continuity
a.
b.
c.
d.
25. A ping-pong ball has an average density of 84.0
kg/m3 and a volume of 3.0x10-5 m3. If the ball is
completely submerged in water, what is the
buoyant force acting on it?
a.
b.
c.
d.
P>P0
P=P0
P<P0
it depends on the density of the material in the
manometer
3N
0.03 N
30 N
0.3 N
4
6.0 m/s
1.0 m/s
1.5 m/s
3.0 m/s
ID: A
Exam 4--PHYS 101--F14
Answer Section
MULTIPLE CHOICE
1. ANS:
TOP:
2. ANS:
3. ANS:
4. ANS:
5. ANS:
6. ANS:
7. ANS:
8. ANS:
9. ANS:
10. ANS:
TOP:
11. ANS:
12. ANS:
13. ANS:
14. ANS:
15. ANS:
16. ANS:
17. ANS:
18. ANS:
19. ANS:
20. ANS:
21. ANS:
22. ANS:
23. ANS:
24. ANS:
TOP:
25. ANS:
26. ANS:
27. ANS:
B
PTS: 1
DIF: 2
7.2 Rotational Motion Under Constant Angular Acceleration
C
PTS: 1
C
PTS: 1
E
PTS: 1
D
PTS: 1
D
PTS: 1
E
PTS: 1
E
PTS: 1
A
PTS: 1
C
PTS: 1
DIF: 2
REF: F14
7.4 Centripetal Acceleration
A
PTS: 1
C
PTS: 1
A
PTS: 1
D
PTS: 1
A
PTS: 1
B
PTS: 1
C
PTS: 1
A
PTS: 1
B
PTS: 1
B
PTS: 1
B
PTS: 1
C
PTS: 1
B
PTS: 1
C
PTS: 1
DIF: 2
9.7 Fluids in Motion | 9.8 Other Applications of Fluid Dynamics
D
PTS: 1
C
PTS: 1
C
PTS: 1
1