Halliday/Resnick/Walker
Fundamentals of Physics 8th edition
Classroom Response System Questions
Chapter 17 Waves II
Reading Quiz Questions
17.2.1. What is the term used to describe the surfaces over which the
oscillations due to a sound wave have the same value?
a) rays
b) wave packets
c) beats
d) phasors
e) wave fronts
17.2.1. What is the term used to describe the surfaces over which the
oscillations due to a sound wave have the same value?
a) rays
b) wave packets
c) beats
d) phasors
e) wave fronts
17.2.2. What is the term used to describe the directed lines that are
perpendicular to wavefronts and indicate their direction of travel?
a) rays
b) wave packets
c) beats
d) phasors
e) phonons
17.2.2. What is the term used to describe the directed lines that are
perpendicular to wavefronts and indicate their direction of travel?
a) rays
b) wave packets
c) beats
d) phasors
e) phonons
17.3.1. Which one of the following expressions correctly gives the
relationship between the speed of sound v in a medium and the
properties of that medium?
elastic property
v
inertial property
a)
b) v  inertial property
elastic property
c) v  (elastic property)(inertial property)
d) The speed is only proportional to the inertial property.
e) The speed is only proportional to the elastic property.
17.3.1. Which one of the following expressions correctly gives the
relationship between the speed of sound v in a medium and the
properties of that medium?
elastic property
v
inertial property
a)
b) v  inertial property
elastic property
c) v  (elastic property)(inertial property)
d) The speed is only proportional to the inertial property.
e) The speed is only proportional to the elastic property.
17.3.2. Which one of the following statements concerning the speed of sound
in a medium is true?
a) The speed of sound is greater for materials that have larger densities than
it is for materials that have smaller densities and all other properties
equal.
b) The speed of sound is greater for materials that have smaller densities
than it is for materials that have larger densities and all other properties
equal.
c) The speed of sound is greater for materials that have larger mass than it is
for materials that have smaller mass and all other properties equal.
d) The speed of sound is greater for materials that have smaller bulk
modulus than it is for materials that have s larger bulk modulus and all
other properties equal.
17.3.2. Which one of the following statements concerning the speed of sound
in a medium is true?
a) The speed of sound is greater for materials that have larger densities than
it is for materials that have smaller densities and all other properties
equal.
b) The speed of sound is greater for materials that have smaller densities
than it is for materials that have larger densities and all other properties
equal.
c) The speed of sound is greater for materials that have larger mass than it is
for materials that have smaller mass and all other properties equal.
d) The speed of sound is greater for materials that have smaller bulk
modulus than it is for materials that have s larger bulk modulus and all
other properties equal.
17.3.3. A girl is playing a trumpet. The sound waves produced are traveling
through air to your ear. Which one of the following statements is false
concerning this situation?
a) A high-frequency sound that the trumpet produces is interpreted as a highpitched sound.
b) Air molecules between the trumpet and your ear vibrate back and forth
parallel to the direction the waves are traveling.
c) The loudness of the sound wave involves the size of the oscillations in air
pressure.
d) The sounds from the trumpet are longitudinal waves.
e) The sound travels at the speed of light to your ear.
17.3.3. A girl is playing a trumpet. The sound waves produced are traveling
through air to your ear. Which one of the following statements is false
concerning this situation?
a) A high-frequency sound that the trumpet produces is interpreted as a highpitched sound.
b) Air molecules between the trumpet and your ear vibrate back and forth
parallel to the direction the waves are traveling.
c) The loudness of the sound wave involves the size of the oscillations in air
pressure.
d) The sounds from the trumpet are longitudinal waves.
e) The sound travels at the speed of light to your ear.
17.3.4. For which one of the following choices does the speed of
sound have the largest value?
a) vacuum
b) air
c) copper
d) alcohol
e) helium
17.3.4. For which one of the following choices does the speed of
sound have the largest value?
a) vacuum
b) air
c) copper
d) alcohol
e) helium
17.3.5. In determining the speed of sound in a solid bar, such as one
made of steel, which of the following choices is not needed?
a) density of the bar
b) bulk modulus
c) Boltzmann’s constant
17.3.5. In determining the speed of sound in a solid bar, such as one
made of steel, which of the following choices is not needed?
a) density of the bar
b) bulk modulus
c) Boltzmann’s constant
17.3.6. A guitar string is plucked and set into vibration. The vibrating
string disturbs the surrounding air, resulting in a sound wave.
Which entry in the table below is correct?
17.3.6. A guitar string is plucked and set into vibration. The vibrating
string disturbs the surrounding air, resulting in a sound wave.
Which entry in the table below is correct?
17.4.1. Which one of the following statements concerning traveling
sound waves in air is false?
a) Traveling sound waves are longitudinal waves.
b) Traveling sound waves consist of alternating regions of
compressed and expanded air.
c) A typical speed of sound in air is 680 m/s.
d) The displacement amplitude of a traveling sound wave may be
described by a sinusoidal function.
e) The pressure amplitude is 90 out of phase relative to the
displacement amplitude of a traveling sound wave.
17.4.1. Which one of the following statements concerning traveling
sound waves in air is false?
a) Traveling sound waves are longitudinal waves.
b) Traveling sound waves consist of alternating regions of
compressed and expanded air.
c) A typical speed of sound in air is 680 m/s.
d) The displacement amplitude of a traveling sound wave may be
described by a sinusoidal function.
e) The pressure amplitude is 90 out of phase relative to the
displacement amplitude of a traveling sound wave.
17.4.2. Which one of the following statements concerning the pressure
amplitude of a traveling sound wave in air is false?
a) The pressure amplitude is inversely proportional to the
displacement amplitude.
b) The pressure amplitude is 90 out of phase relative to the displacement
amplitude.
c) A negative value of the pressure amplitude corresponds to an expansion
of the air.
d) The pressure amplitude depends on the air density.
e) When the displacement amplitude is at its maximum value, the pressure
amplitude is zero Pa.
17.4.2. Which one of the following statements concerning the pressure
amplitude of a traveling sound wave in air is false?
a) The pressure amplitude is inversely proportional to the
displacement amplitude.
b) The pressure amplitude is 90 out of phase relative to the displacement
amplitude.
c) A negative value of the pressure amplitude corresponds to an expansion
of the air.
d) The pressure amplitude depends on the air density.
e) When the displacement amplitude is at its maximum value, the pressure
amplitude is zero Pa.
17.5.1. The drawing shows two sets of sound waves, created by two sources labeled
"A" and "B." The black half-circles represent wave crests from A, and the grey
half-circles represent wave crests from B. Suppose that individual wave crests
from either source A or source B alone are at +5 µm relative to the undisturbed
air molecule positions. What is the displacement of the air molecules at the
point marked "x" that is at the mid-point between to crests on each wave?
a) +10 µm
b) +5 µm
c) 0
d) 5 µm
e) 10 µm
17.5.1. The drawing shows two sets of sound waves, created by two sources labeled
"A" and "B." The black half-circles represent wave crests from A, and the grey
half-circles represent wave crests from B. Suppose that individual wave crests
from either source A or source B alone are at +5 µm relative to the undisturbed
air molecule positions. What is the displacement of the air molecules at the
point marked "x" that is at the mid-point between to crests on each wave?
a) +10 µm
b) +5 µm
c) 0
d) 5 µm
e) 10 µm
17.5.2. Two pulses of identical shape travel toward each other in opposite
directions on a string, as shown in the figure. Which one of the
following statements concerning this situation is true?
a) The pulses will pass through each other and produce beats.
b) As the pulses pass through each other, they will interfere destructively.
c) The pulses will interfere to produce a standing wave.
d) The pulses will reflect from each other.
e) The pulses will diffract from each other.
17.5.2. Two pulses of identical shape travel toward each other in opposite
directions on a string, as shown in the figure. Which one of the
following statements concerning this situation is true?
a) The pulses will pass through each other and produce beats.
b) As the pulses pass through each other, they will interfere destructively.
c) The pulses will interfere to produce a standing wave.
d) The pulses will reflect from each other.
e) The pulses will diffract from each other.
17.5.3. Sound waves are emitted from two speakers. Which one of the
following statements about sound wave interference is false?
a) In a region where both destructive and constructive interference occur,
energy is not conserved.
b) Destructive interference occurs when two waves are exactly out of
phase when they meet.
c) Interference redistributes the energy carried by the individual waves.
d) Constructive interference occurs when two waves are exactly in phase
when they meet.
e) Sound waves undergo diffraction as they exit each speaker.
17.5.3. Sound waves are emitted from two speakers. Which one of the
following statements about sound wave interference is false?
a) In a region where both destructive and constructive interference occur,
energy is not conserved.
b) Destructive interference occurs when two waves are exactly out of
phase when they meet.
c) Interference redistributes the energy carried by the individual waves.
d) Constructive interference occurs when two waves are exactly in phase
when they meet.
e) Sound waves undergo diffraction as they exit each speaker.
17.6.1. Which of the following expressions correctly relates the
amplitude sm of a sound wave to its intensity?
a) I  sm
1
b) I 
sm
2
c) I  sm
1
d) I  2
sm
e) I 
sm
17.6.1. Which of the following expressions correctly relates the
amplitude sm of a sound wave to its intensity?
a) I  sm
1
b) I 
sm
2
c) I  sm
1
d) I  2
sm
e) I 
sm
17.6.2. Complete the following statement: The intensity of sound that
is emitted isotropically
a) is inversely proportional to the square of the distance from the
source.
b) is proportional to the square of the distance from the source.
c) is inversely proportional to the square of the amplitude of the wave.
d) is proportional to the distance from the source.
e) is inversely proportional to the distance from the source.
17.6.2. Complete the following statement: The intensity of sound that
is emitted isotropically
a) is inversely proportional to the square of the distance from the
source.
b) is proportional to the square of the distance from the source.
c) is inversely proportional to the square of the amplitude of the wave.
d) is proportional to the distance from the source.
e) is inversely proportional to the distance from the source.
17.6.3. Complete the following statement: The power of a sound wave
that is emitted isotropically
a) is inversely proportional to the square of the distance from the
source.
b) is proportional to the square of the distance from the source.
c) is inversely proportional to the square of the amplitude of the wave.
d) is inversely proportional to the distance from the source.
e) None of the above statements are true.
17.6.3. Complete the following statement: The power of a sound wave
that is emitted isotropically
a) is inversely proportional to the square of the distance from the
source.
b) is proportional to the square of the distance from the source.
c) is inversely proportional to the square of the amplitude of the wave.
d) is inversely proportional to the distance from the source.
e) None of the above statements are true.
17.6.4. Which one of the following statements best describes the concept
of sound intensity?
a) Sound intensity is the amount of energy the sound waves carries at a
particular location.
b) Sound intensity is the sound power that passes perpendicularly
through a surface divided by the amplitude of the wave.
c) Sound intensity is the amplitude of the wave.
d) Sound intensity is the constant power per unit area of a sound wave as
it travels from one location to another.
e) Sound intensity is the sound power that passes perpendicularly
through a surface divided by the area of that surface.
17.6.4. Which one of the following statements best describes the concept
of sound intensity?
a) Sound intensity is the amount of energy the sound waves carries at a
particular location.
b) Sound intensity is the sound power that passes perpendicularly
through a surface divided by the amplitude of the wave.
c) Sound intensity is the amplitude of the wave.
d) Sound intensity is the constant power per unit area of a sound wave as
it travels from one location to another.
e) Sound intensity is the sound power that passes perpendicularly
through a surface divided by the area of that surface.
17.6.5. The threshold of hearing is the smallest sound intensity that a
human ear can hear. What intensity corresponds to the threshold
of hearing?
a) 1012 W/m2
b) 1010 W/m2
c) 108 W/m2
d) 106 W/m2
e) 104 W/m2
17.6.5. The threshold of hearing is the smallest sound intensity that a
human ear can hear. What intensity corresponds to the threshold
of hearing?
a) 1012 W/m2
b) 1010 W/m2
c) 108 W/m2
d) 106 W/m2
e) 104 W/m2
17.6.6. The sound intensity level is reported in decibels. If one
doubles the intensity of sound, by what factor does the perceived
loudness, in decibels, change?
a) 10 dB
b) 20 dB
c) 3 dB
d) 2 dB
e) 5 dB
17.6.6. The sound intensity level is reported in decibels. If one
doubles the intensity of sound, by what factor does the perceived
loudness, in decibels, change?
a) 10 dB
b) 20 dB
c) 3 dB
d) 2 dB
e) 5 dB
17.6.7. The sound intensity level is reported in decibels. If the sound
intensity is at the threshold for hearing, what is the sound intensity
level in decibels?
a) zero dB
b) 1 dB
c) 12 dB
d) 10 dB
e) 3 dB
17.6.7. The sound intensity level is reported in decibels. If the sound
intensity is at the threshold for hearing, what is the sound intensity
level in decibels?
a) zero dB
b) 1 dB
c) 12 dB
d) 10 dB
e) 3 dB
17.7.1. A wire of mass m and length L carries a transverse wave. If the
tension applied to the wire is T, which one of the following
statements concerning the wave is true?
a) The wavelength of the wave depends only on L.
b) The wavelength of the wave depends on L, m, and T.
c) The speed of the wave depends on L, m, and T.
d) The speed of the wave depends only on m and L.
e) Statements (a) and (d) are both true.
17.7.1. A wire of mass m and length L carries a transverse wave. If the
tension applied to the wire is T, which one of the following
statements concerning the wave is true?
a) The wavelength of the wave depends only on L.
b) The wavelength of the wave depends on L, m, and T.
c) The speed of the wave depends on L, m, and T.
d) The speed of the wave depends only on m and L.
e) Statements (a) and (d) are both true.
17.7.2. The drawings show standing waves of sound in six organ pipes
of the same length. Each pipe has one end open and the other end
closed. Some of the drawings show situations that are not
possible. Which one(s) is(are) not possible?
a) 4 only
b) 1 and 4
c) 5 and 6
d) 2 and 3
e) 4 and 5
17.7.2. The drawings show standing waves of sound in six organ pipes
of the same length. Each pipe has one end open and the other end
closed. Some of the drawings show situations that are not
possible. Which one(s) is(are) not possible?
a) 4 only
b) 1 and 4
c) 5 and 6
d) 2 and 3
e) 4 and 5
17.7.3. The drawings show standing waves of sound in six organ pipes
of the same length. Each pipe has one end open and the other end
closed. Some of the drawings show situations that are not
possible. Which one of these tubes emits a sound with the lowest
frequency?
a) 1
b) 2
c) 3
d) 4
e) 6
17.7.3. The drawings show standing waves of sound in six organ pipes
of the same length. Each pipe has one end open and the other end
closed. Some of the drawings show situations that are not
possible. Which one of these tubes emits a sound with the lowest
frequency?
a) 1
b) 2
c) 3
d) 4
e) 6
17.8.1. Under what conditions can you hear beats of sound waves?
a) when the wave is a standing wave
b) when the wave is refracted
c) when the wave is diffracted
d) when two waves of slightly different frequency combine
e) when two waves of slightly different amplitude combine
17.8.1. Under what conditions can you hear beats of sound waves?
a) when the wave is a standing wave
b) when the wave is refracted
c) when the wave is diffracted
d) when two waves of slightly different frequency combine
e) when two waves of slightly different amplitude combine
17.8.2. Which one of the following superpositions will result in beats?
a) the superposition of waves that are identical except for slightly
different amplitudes
b) the superposition of waves that are identical except for slightly
different frequencies
c) the superposition of identical waves that travel in the same
direction
d) the superposition of identical waves that travel in opposite
directions
e) the superposition of waves that travel with different speeds
17.8.2. Which one of the following superpositions will result in beats?
a) the superposition of waves that are identical except for slightly
different amplitudes
b) the superposition of waves that are identical except for slightly
different frequencies
c) the superposition of identical waves that travel in the same
direction
d) the superposition of identical waves that travel in opposite
directions
e) the superposition of waves that travel with different speeds
17.8.3. A guitar string produces 4 beats/s when sounded with a 250 Hz
tuning fork and 9 beats per second when sounded with a 255 Hz
tuning fork. What is the vibrational frequency of the string?
a) 246 Hz
b) 240 Hz
c) 259 Hz
d) 254 Hz
e) 263 Hz
17.8.3. A guitar string produces 4 beats/s when sounded with a 250 Hz
tuning fork and 9 beats per second when sounded with a 255 Hz
tuning fork. What is the vibrational frequency of the string?
a) 246 Hz
b) 240 Hz
c) 259 Hz
d) 254 Hz
e) 263 Hz
17.9.1. On a warm spring day, you are waiting at a red traffic light listening to your favorite
radio station with the windows down. The driver in a car passing you in the left turn lane
at a constant speed happens to be listening to the same radio station. What do you notice
as the car approaches and passes you?
a) The sound from the passing car seems to be at a lower frequency when approaching and at
a higher frequency when moving away compared to the sound from your radio.
b) The sound from the passing car seems to be at a higher frequency when approaching and at
a lower frequency when moving away compared to the sound from your radio.
c) As the car approaches, the shift to higher frequencies increases as the distance decreases
between the two cars.
d) As the car approaches, the shift to lower frequencies increases as the distance decreases
between the two cars.
e) As the car approaches, the shift to lower frequencies decreases as the distance decreases
between the two cars.
17.9.1. On a warm spring day, you are waiting at a red traffic light listening to your favorite
radio station with the windows down. The driver in a car passing you in the left turn lane
at a constant speed happens to be listening to the same radio station. What do you notice
as the car approaches and passes you?
a) The sound from the passing car seems to be at a lower frequency when approaching and at
a higher frequency when moving away compared to the sound from your radio.
b) The sound from the passing car seems to be at a higher frequency when approaching and at
a lower frequency when moving away compared to the sound from your radio.
c) As the car approaches, the shift to higher frequencies increases as the distance decreases
between the two cars.
d) As the car approaches, the shift to lower frequencies increases as the distance decreases
between the two cars.
e) As the car approaches, the shift to lower frequencies decreases as the distance decreases
between the two cars.
17.9.2. Which of the following occurs when the Doppler effect is
produced by a moving source of sound?
a) interference
b) superposition
c) sound intensity changes
d) frequency changes
e) beats
17.9.2. Which of the following occurs when the Doppler effect is
produced by a moving source of sound?
a) interference
b) superposition
c) sound intensity changes
d) frequency changes
e) beats
17.9.3. Astronomers can determine the velocity of a galaxy relative to the Earth by
observing the light waves emitted by certain elements. If the light frequency
from hydrogen atoms is shifted toward a lower frequency as compared to the
light emitted from hydrogen atoms on Earth, which one of the following
statements correctly describes the velocity of the galaxy?
a) The galaxy is moving away from the Earth.
b) The galaxy is moving toward the Earth.
c) The galaxy is moving along a direction that is perpendicular to the line
connecting the Earth and the galaxy.
d) The galaxy is not moving relative to the Earth.
e) There is too little information given to determine the direction of the velocity of
the galaxy.
17.9.3. Astronomers can determine the velocity of a galaxy relative to the Earth by
observing the light waves emitted by certain elements. If the light frequency
from hydrogen atoms is shifted toward a lower frequency as compared to the
light emitted from hydrogen atoms on Earth, which one of the following
statements correctly describes the velocity of the galaxy?
a) The galaxy is moving away from the Earth.
b) The galaxy is moving toward the Earth.
c) The galaxy is moving along a direction that is perpendicular to the line
connecting the Earth and the galaxy.
d) The galaxy is not moving relative to the Earth.
e) There is too little information given to determine the direction of the velocity of
the galaxy.
17.9.4. You are riding a bicycle along the side of a road when an
ambulance comes up behind you with its siren on. As the
ambulance passes, you notice that the sound of the siren changes.
How does it change as it passes?
a) The frequency decreases and then increases.
b) The frequency increases and then decreases.
c) The frequency continually increases.
d) The frequency continually decreases.
e) The frequency decreases to a lower frequency.
17.9.4. You are riding a bicycle along the side of a road when an
ambulance comes up behind you with its siren on. As the
ambulance passes, you notice that the sound of the siren changes.
How does it change as it passes?
a) The frequency decreases and then increases.
b) The frequency increases and then decreases.
c) The frequency continually increases.
d) The frequency continually decreases.
e) The frequency decreases to a lower frequency.
17.9.5. In the formulas for calculating the frequency an observer hears
during the Doppler effect, what is the term vS?
a) speed of the observer
b) speed of sound
c) speed of the source
d) speed of light
e) wind speed
17.9.5. In the formulas for calculating the frequency an observer hears
during the Doppler effect, what is the term vS?
a) speed of the observer
b) speed of sound
c) speed of the source
d) speed of light
e) wind speed
17.10.1. Under which of the following conditions does a shock wave
occur?
a) when two waves of differing frequencies superpose
b) when the temperature of air is greater than the temperature of the
source of the sound
c) when the pressure amplitude exceeds the maximum pressure
amplitude that the human ear can tolerate
d) when the source of a sound wave exceeds the speed of sound
e) when the sound intensity level exceeds 130 dB
17.10.1. Under which of the following conditions does a shock wave
occur?
a) when two waves of differing frequencies superpose
b) when the temperature of air is greater than the temperature of the
source of the sound
c) when the pressure amplitude exceeds the maximum pressure
amplitude that the human ear can tolerate
d) when the source of a sound wave exceeds the speed of sound
e) when the sound intensity level exceeds 130 dB