Halliday D., Resnick R., Walker J. Fundamentals of physics. Test Bank
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66. A constriction in a pipe reduces its diameter from 4.0cm to 2.0 cm. Where the pipe is narrow
the water speed is 8.0m/s. Where it is wide the water speed is:
A. 2.0m/s
B. 4.0m/s
C. 8.0m/s
D. 16 m/s
E. 32 m/s
ans: C
67. Water flows from a 6.0-cm diameter pipe into an 8.0-cm diameter pip e. The speed in the 6 .0-cm
pipeis5.0m/s . The speed in the 8.0-cm pipe is:
A. 2.8m/s
B. 3.7m/s
C. 6.6m/s
D. 8.8m/s
E. 9.9m/s
ans: A
68. A lawn sprinkler is made of a 1.0-cm diameter garden hose with one end closed and 25 holes,
each with a diameter of 0.050 cm, cut near the closed end. If water flows at 2.0m/s in the hose,
the speed of the water leaving a hole is:
A. 2.0m/s
B. 32 m/s
C. 40 m/s
D. 600 m/s
E. 800 m/s
ans: B
69. Bernoulli’s equation can be derived from the conservation of:
A. energy
B. mass
C. angular momentum
D. volume
E. pressure
ans: A
70. Which of the following assumptions is NOT made in the derivation of Bernoulli’s equation?
A. Assume streamline flow
B. Neglect viscosity
C. Neglect friction
D. Neglect gravity
E. Neglect turbulence
ans: D
Chapter 14: FLUIDS 221
71. The quantity y appearing in Bernoulli’s equation MUST be measured:
A. upward from the center of Earth
B. upward from the surface of Earth
C. upward from the lowest point in the flow
D. downward from the highest point in the flow
E. upward from any convenient level
ans: E
72. Water flows through a constriction in a horizontal pipe. As it enters the constriction, the
water’s:
A. speed increases and pressure decreases
B. speed increases and pressure remains constant
C. speed increases and pressure increases
D. speed decreases and pressure increases
E. speed decreases and pressure decreases
ans: A
73. Water is pumped through the hose shown below, from a lower level to an upper level. Compared
to the water at point 1, the water at point 2:
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2
1
←
←
upper level
lower level
A. has greater speed and greater pressure
B. has greater speed and less pressure
C. has less speed and less pressure
D. has less speed and greater pressure
E. has greater speed and the same pressure
ans: B
222 Chapter 14: FLUIDS
74. A non-viscous incompressible liquid is flowing through a horizontal pipe of constant cross
section. Bernoulli’s equation and the equation of continuity predict that the drop in pressure
along the pipe:
A. is zero
B. depends on the length of the pipe
C. depends on the fl uid velocity
D. depends on the cross-sectional area of the pipe
E. depends on the height of the pipe
ans: A
75. A non-viscous incompressible fluid is pumped steadily into the narrow end of a long tapered
pipe and emerges from the wide end. The pressure at the input is greater than at the output.
A possible explanation is:
A. the fluid speed increases from input to output
B. the fluid speed is the same at the two ends
C. the fluid is flowing uphill
D. the fluid is flowing downhill
E. the fluid is flowing horizontally
ans: C
76. Water is pumped into one end of a long pipe at the rate of 40 L/min. It emerges at the other
end at 24 L/min. A possible reason for this decrease in flow is:
A. the water is being pumped uphill
B. the water is being pumped downhill
C. the diameter of the pipe is not the same at the two ends
D. friction in the pipe
E. a leak in the pipe
ans: E
77. Consider a pipe containing a fluid, with the fluid being at rest. To apply Bernoulli’s equation
to this situation:
A. set v equal to zero because there is no motion
B. set g equal to zero because there is no acceleration
C. set v and g both equal to zero
D. set p equal to the atmospheric pressure
E. cannot be done, Bernoulli’s equation applies only to fluids in motion
ans: A
78. Water (density = 1.0 × 10
3
kg/m
3
) flows through a horizontal tapered pipe. At the wide end
its speed is 4.0m/s. The difference in pressure between the two ends is 4.5 × 10
3
Pa. The speed
of the water at the narrow end is:
A. 2.6m/s
B. 3.4m/s
C. 4.0m/s
D. 4.5m/s
E. 5.0m/s
ans: E
Chapter 14: FLUIDS 223
79. Water is streaming downward from a faucet opening with an area of 3.0 × 10
−5
m
2
. It leaves
the faucet with a speed of 5.0m/s. The cross-sectional area of the stream 0.50 m below the
faucet is:
A. 1.5 × 10
−5
m
2
B. 2.0 × 10
−5
m
2
C. 2.5 × 10
−5
m
2
D. 3.0 × 10
−5
m
2
E. 3.5 × 10
−5
m
2
ans: C
80. A large water tank, open at the top, has a small hole in the bottom. When the water level is
30 m above the bottom of the tank, the speed of the water leaking from the hole:
A. is 2.5m/s
B. is 24 m/s
C. is 44 m/s
D. cannot be calculated unless the area of the hole is given
E. cannot be calculated unless the areas of the hole and tank are given
ans: B
81. A large tank filled with water has two holes in the bottom, one with twice the radius of the
other. In steady flow the speed of water leaving the larger hole is
the speed of the water
leaving the smaller.
A. twice
B. four times
C. half
D. one-fourth
E. the same as
ans: E
82. A non-viscous incompressible fluid is pumped steadily up a vertical pipe with uniform cross
section. The difference in pressure between points at the top and bottom:
A. is the same as it would be if the fluid were motionless
B. is greater at higher flow rates than at lower flow rates
C. is less at higher flow rates than at lower flow rates
D. does not depend on the density of the fluid
E. is zero
ans: A
224 Chapter 14: FLUIDS
83. A water line enters a house 2.0 m below ground. A smaller diameter pipe carries water to a
faucet 5.0 m above ground, on the second floor. Water flowsat2.0m/s in the main line and at
7.0m/s on the second floor. Take the density of water to be 1.0 × 10
3
kg/m
3
. The difference
in pressure between the main line and the second floor is:
A. 7.15 × 10
4
Pa with the main line at the higher pressure
B. 2.65 × 10
4
Pa with the main line at the higher pressure
C. 7.15 × 10
4
Pa with the main line at the lower pressure
D. 2.65 × 10
4
Pa with the main line at the lower pressure
E. 9.4 × 10
4
Pa with the main line at the higher pressure
ans: A
84. A person blows across the top of one arm of a U-tube partially filled with water. The water in
that arm:
A. rises slightly
B. drops slightly
C. remains at the same height
D. rises if the blowing is soft but drops if it is hard
E. rises if the blowing is hard but drops if it is soft
ans: A
Chapter 14: FLUIDS 225
Chapter 15: OSCILLATIONS
1. In simple harmonic motion, the restoring force must be proportional to the:
A. amplitude
B. frequency
C. velocity
D. displacement
E. displacement squared
ans: D
2. An oscillatory motion must be simple harmonic if:
A. the amplitude is small
B. the potential energy is equal to the kinetic energy
C. the motion is along the arc of a circle
D. the acceleration varies sinusoidally with time
E. the derivative, dU/dx, of the potential energy is negative
ans: D
3. In simple harmonic motion, the magnitude of the acceleration is:
A. constant
B. proportional to the displacement
C. inversely proportional to the displacement
D. greatest when the velocity is greatest
E. never greater than g
ans: B
4. A particle is in simple harmonic motion with period T . At time t = 0 it is at the equilibrium
point. Of the following times, at which time is it furthest from the equilibrium point?
A. 0.5T
B. 0.7T
C. T
D. 1.4T
E. 1.5T
ans: B
5. A particle moves back and forth along the x axis from x = −x
m
to x =+x
m
, in simple
harmonic motion with period T . At time t = 0 it is at x =+x
m
. When t =0.75T :
A. it is at x = 0 and is traveling toward x =+x
m
B. it is at x = 0 and is traveling toward x = −x
m
C. it at x =+x
m
and is at rest
D. it is between x = 0 and x =+x
m
and is traveling toward x = −x
m
E. it is between x = 0 and x = −x
m
and is traveling toward x = −x
m
ans: A
226 Chapter 15: OSCILLATIONS
6. A particle oscillating in simple harmonic motion is:
A. never in equilibrium because it is in motion
B. never in equilibrium because there is always a force
C. in equilibrium at the ends of its path because its velocity is zero there
D. in equilibrium at the center of its path because the acceleration is zero there
E. in equilibrium at the ends of its path because the acceleration is zero there
ans: D
7. An object is undergoing simple harmonic motion. Throughout a complete cycle it:
A. has constant speed
B. has varying amplitude
C. has varying period
D. has varying acceleration
E. has varying mass
ans: D
8. When a body executes simple harmonic motion, its acceleration at the ends of its path must
be:
A. zero
B. less than g
C. more than g
D. suddenly changing in sign
E. none of these
ans: E
9. A particle is in simple harmonic motion with period T . At time t = 0 it is halfway between
the equilibrium point and an end point of its motion, traveling toward the end point. The next
time it is at the same place is:
A. t = T
B. t = T/2
C. t = T/4
D. t = T/8
E. none of the above
ans: E
10. An object attached to one end of a spring makes 20 complete oscillations in 10 s. Its period is:
A. 2 Hz
B. 10 s
C. 0.5Hz
D. 2 s
E. 0.50 s
ans: E
Chapter 15: OSCILLATIONS 227
11. An object attached to one end of a spring makes 20 vibrations in 10 s. Its frequency is:
A. 2 Hz
B. 10 s
C. 0.05 Hz
D. 2 s
E. 0.50 s
ans: A
12. An object attached to one end of a spring makes 20 vibrations in 10 s. Its angular frequency
is:
A. 0.79 rad/s
B. 1.57 rad/s
C. 2.0 rad/s
D. 6.3 rad/s
E. 12.6 rad/s
ans: E
13. Frequency f and angular frequency ω are related by
A. f = πω
B. f =2πω
C. f = ω/π
D. f = ω/2π
E. f =2ω/π
ans: D
14. A block attached to a spring oscillates in simple harmonic motion along the x axis. The limits
of its motion are x = 10 cm and x = 50 cm and it goes from one of these extremes to the other
in 0.25 s. Its amplitude and frequency are:
A. 40 cm, 2 Hz
B. 20 cm, 4 Hz
C. 40 cm, 2 Hz
D. 25 cm, 4 Hz
E. 20 cm, 2 Hz
ans: B
15. A weight suspended from an ideal spring oscillates up and down with a period T . If the
amplitude of the oscillation is doubled, the period will be:
A. T
D. 1.5T
B. 2T
C. T/2
E. 4T
ans: A
228 Chapter 15: OSCILLATIONS
16. In simple harmonic motion, the magnitude of the acceleration is greatest when:
A. the displacement is zero
B. the displacement is maximum
C. the speed is maximum
D. the force is zero
E. the speed is between zero and its maximum
ans: B
17. In simple harmonic motion, the displacement is maximum when the:
A. acceleration is zero
B. velocity is maximum
C. velocity is zero
D. kinetic energy is maximum
E. momentum is maximum
ans: C
18. In simple harmonic motion:
A. the acceleration is greatest at the maximum displacement
B. the velocity is greatest at the maximum displacement
C. the period depends on the amplitude
D. the acceleration is constant
E. the acceleration is greatest at zero displacement
ans: A
19. The amplitude and phase constant of an oscillator are determined by:
A. the frequency
B. the angular frequency
C. the initial displacement alone
D. the initial velocity alone
E. both the initial displacement and velocity
ans: E
20. Two identical undamped oscillators have the same amplitude of oscillation only if:
A. they are started with the same displacement x
0
B. they are started with the same velocity v
0
C. they are started with the same phase
D. they are started so the combination ω
2
x
2
0
+ v
2
0
is the same
E. they are started so the combination x
2
0
+ ω
2
v
2
0
is the same
ans: D
21. The amplitude of any oscillator can be doubled by:
A. doubling only the initial displacement
B. doubling only the initial speed
C. doubling the initial displacement and halving the initial speed
D. doubling the initial speed and halving the initial displacement
E. doubling both the initial displacement and the initial speed
ans: E
Chapter 15: OSCILLATIONS 229
22. It is impossible for two particles, each executing simple harmonic motion, to remain in phase
with each other if they have different:
A. masses
B. periods
C. amplitudes
D. spring constants
E. kinetic energies
ans: B
23. The acceleration of a body executing simple harmonic motion leads the velocity by what phase?
A. 0
B. π/8 rad
C. π/4 rad
D. π/2 rad
E. π rad
ans: D
24. The displacement of an object oscillating on a spring is given by x(t)=x
m
cos(ωt + φ). If the
initial displacement is zero and the initial velocity is in the negative x direction, then the phase
constant φ is:
A. 0
B. π/2 rad
C. π rad
D. 3π/2 rad
E. 2π rad
ans: B
25. The displacement of an object oscillating on a spring is given by x(t)=x
m
cos(ωt + φ). If
the object is initially displaced in the negative x direction and given a negative initial velocity,
then the phase constant φ is between:
A. 0 and π/2 rad
B. π/2 and π rad
C. π and 3π/2 rad
D. 3π/2 and 2 π rad
E. none of the above (φ is exactly 0, π/2, π,or3π/2 rad)
ans: B
26. A certain spring elongates 9.0 mm when it is suspended vertically and a block of mass M is
hung on it. The natural angular frequency of this block-spring system:
A. is 0.088 rad/s
B. is 33 rad/s
C. is 200 rad/s
D. is 1140 rad/s
E. cannot be computed unless the value of M is given
ans: B
230 Chapter 15: OSCILLATIONS