Waves—II Complete Test Bank Halliday Ch.17 - Fundamentals of Physics 11e Complete Test Bank by David Halliday. DOCX document preview.
Chapter: Chapter 17
Learning Objectives
LO 17.1.0 Solve problems related to speed of sound.
LO 17.1.1 Distinguish between a longitudinal wave and a transverse wave.
LO 17.1.2 Explain wavefronts and rays.
LO 17.1.3 Apply the relationship between the speed of sound through a material, the material’s bulk modulus, and the material’s density.
LO 17.1.4 Apply the relationship between the speed of sound, the distance travelled by a sound wave, and the time required to travel that distance.
LO 17.2.0 Solve problems related to traveling sound waves.
LO 17.2.1 For any particular time and position, calculate the displacement s(x,t) of an element of air as a sound wave travels through its location.
LO 17.2.2 Given a displacement function s(x,t) for a sound wave, calculate the time between two given displacements.
LO 17.2.3 Apply the relationships between wave speed v, angular frequency ω, angular wavenumber k, wavelength λ, period T, and frequency f.
LO 17.2.4 Sketch a graph of the displacement s(x) of the element as a function of position, and identify the amplitude sm and wavelength λ.
LO 17.2.5 For any particular time and position, calculate the pressure variation Δρ (variation from atmospheric pressure) of an element of air as a sound wave travels through its location.
LO 17.2.6 Sketch a graph of the pressure variation Δρ(x) of an element as a function of position, and identify the amplitude Δρm and wavelength λ.
LO 17.2.7 Apply the relationship between pressure-variation amplitude Δρm and displacement amplitude sm.
LO 17.2.8 Given a graph of position s versus time for a sound wave, determine the amplitude sm and the period T.
LO 17.2.9 Given a graph of pressure variation Δρ versus time for a sound wave, determine the amplitude Δρm and the period T.
LO 17.3.0 Solve problems related to interference.
LO 17.3.1 If two waves with the same wavelength begin in phase but reach a common point by traveling along different paths, calculate their phase difference φ at that point by relating the path-length difference ΔL to the wavelength λ.
LO 17.3.2 Given the phase difference between two sound waves with the same amplitude, wavelength, and travel direction, determine the type of interference between the waves (fully destructive interference, fully constructive interference, or indeterminate interference).
LO 17.3.3 Convert a phase difference between radians, degrees, and number of wavelengths.
LO 17.4.0 Solve problems related to intensity and sound level.
LO 17.4.1 Calculate the sound intensity I at a surface as the ratio of the power P to the surface area A.
LO 17.4.2 Apply the relationship between the sound intensity I and the displacement amplitude sm of the sound wave.
LO 17.4.3 Identify an isotropic point source of sound.
LO 17.4.4 For an isotropic point source, apply the relationship involving the emitting power Ps, the distance r to a detector, and the sound intensity I at the detector.
LO 17.4.5 Apply the relationship between the sound level β, the sound intensity I, and the standard reference intensity I0.
LO 17.4.6 Evaluate a logarithm function (log) and an antilogarithm function (log-1).
LO 17.4.7 Relate the change in sound level to the change in sound intensity.
LO 17.5.0 Solve problems related to sources of musical sound.
LO 17.5.1 Using standing wave patterns for string waves, sketch the standing wave patterns for the first several acoustical harmonics of a pipe with only one open end and with two open ends.
LO 17.5.2 For a standing wave of sound, relate the distance between nodes and the wavelength.
LO 17.5.3 Identify which type of pipe has even harmonics.
LO 17.5.4 For any given harmonic and for a pipe with only one open end or with two open ends, apply the relationships between the pipe length L, the speed of sound v, the wavelength λ, the harmonic frequency f, and the harmonic number n.
LO 17.6.0 Solve problems related to beats.
LO 17.6.1 Explain how beats are produced.
LO 17.6.2 Add the displacement equations for two sound waves of the same amplitude and slightly different angular frequencies to find the displacement equation of the resultant wave and identify the time-varying amplitude.
LO 17.6.3 Apply the relationship between the beat frequency and the frequencies of two sound waves of the same amplitude and slightly different angular frequencies.
LO 17.7.0 Solve problems related to the Doppler effect.
LO 17.7.1 Identify that the Doppler effect is the shift in frequency due to the relative motion between a sound source and a detector intercepting that sound.
LO 17.7.2 Identify that in calculating the Doppler shift in sound, the speeds in the calculations are measured relative to the air, which may be moving.
LO 17.7.3 Calculate the shift in sound frequency for (a) a source moving either directly toward or away from a stationary detector, (b) a detector moving either directly toward or away from a stationary source, and (c) both source and detector moving.
LO 17.7.4 Identify that for relative motion between a sound source and a sound detector, motion toward tends to shift the frequency up and motion away tends to shift it down.
LO 17.8.0 Solve problems related to supersonic speeds, shock waves.
LO 17.8.1 Sketch the bunching of wavefronts for a sound source traveling at the speed of sound or faster.
LO 17.8.2 Calculate the Mach number for a sound source exceeding the speed of sound.
LO 17.8.3 For a sound source exceeding the speed of sound, apply the relationship between the Mach cone angle, the speed of sound, and the speed of the source.
Multiple Choice
1. The speed of a sound wave is determined by:
A) its amplitude
B) its intensity
C) its pitch
D) number of overtones present
E) the transmitting medium
Difficulty: E
Section: 17-1
Learning Objective 17.1.0
2. The difference between transverse and longitudinal waves:
A) depends on the frequency of the wave
B) depends on the wavelength of the wave
C) depends on the direction of propagation of the wave
D) depends on the direction of oscillation of the medium relative to the direction of propagation of the wave
E) there is no difference, they are just two ways of describing the same phenomenon
Difficulty: E
Section: 17-1
Learning Objective 17.1.1
3. What is a wavefront?
A) A set of points on a wave that are all traveling in the same direction.
B) The front of the wave is the highest point on the wave.
C) The front of the wave faces the direction the wave is traveling.
D) A set of points on a wave that all have the same wavelength.
E) A set of points on a wave that all have the same displacement.
Difficulty: E
Section: 17-1
Learning Objective 17.1.2
4. The bulk modulus of water is 2.2 x 109 Pa, and its density is 1.0 x 103 kg/m3. What is the speed of sound in water?
A) 1.5 x 103 m/s
B) 2.2 x 103 m/s
C) 3.5 x 103 m/s
D) 4.5 x 103 m/s
E) 2.2 x 106 m/s
Difficulty: M
Section: 17-1
Learning Objective 17.1.3
5. Take the speed of sound to be 340 m/s. A thunder clap is heard about 3 s after the lightning is seen. The source of both light and sound is:
A) moving overhead faster than the speed of sound
B) emitting a much higher frequency than is heard
C) emitting a much lower frequency than is heard
D) about 1000 m away
E) much more than 1000 m away
Difficulty: E
Section: 17-1
Learning Objective 17.1.4
6. A sound wave has a wavelength of 3.0 m. The distance from a compression center to the adjacent rarefaction center is:
A) 0.75 m
B) 1.5 m
C) 3.0 m
D) need to know wave speed
E) need to know frequency
Difficulty: E
Section: 17-2
Learning Objective 17.2.0
7. Which of the following properties of a sound wave determine its "pitch"?
A) amplitude
B) distance form source to detector
C) frequency
D) phase
E) speed
Difficulty: E
Section: 17-2
Learning Objective 17.2.0
8. The longitudinal displacement of a mass element in a medium as a sound wave passes through it is given by s = sm cos (kx – ωt). Consider a sound wave of frequency 440 Hz and wavelength 0.75m. If sm = 12 µm, what is the displacement of an element of air located at x = 1.2 m at time t = 0.11 s?
A) 3.7 µm
B) 4.9 µm
C) 6.0 µm
D) 8.2 µm
E) 12 µm
Difficulty: M
Section: 17-2
Learning Objective 17.2.1
9. The longitudinal displacement of a mass element in a medium as a sound wave passes through it is given by s = sm cos (kx – ωt). Consider a sound wave of frequency 440 Hz and wavelength 0.75m. If sm = 12 µm, how long does it take an element of air to move from a displacement of 12 µm to a displacement of 0 µm?
A) 0.57 ms
B) 1.1 ms
C) 2.3 ms
D) 3.4 ms
E) 4.6 ms
Difficulty: E
Section: 17-2
Learning Objective 17.2.2
10. A fire whistle emits a tone of 170 Hz. Take the speed of sound in air to be 340 m/s. The wavelength of this sound is about:
A) 0.5 m
B) 1.0 m
C) 2.0 m
D) 3.0 m
E) 340 m
Difficulty: E
Section: 17-2
Learning Objective 17.2.3
11. During a time interval of exactly one period of vibration of a tuning fork, the emitted sound travels a distance:
A) equal to the length of the tuning fork
B) equal to twice the length of the tuning fork
C) of about 330 m
D) which decreases with time
E) of one wavelength in air
Difficulty: E
Section: 17-2
Learning Objective 17.2.3
12. At points in a sound wave where the gas is maximally compressed, the pressure
A) is a maximum
B) is a minimum
C) is equal to the ambient value
D) is greater than the ambient value but less than the maximum
E) is less than the ambient value but greater than the minimum
Difficulty: E
Section: 17-2
Learning Objective 17.2.5
13. The speed of sound in air is 340 m/s, and the density of air is 1.2 kg/m3. If the displacement amplitude of a 440-Hz sound wave is 10 µm, what is its pressure-variation amplitude?
A) 1.8 Pa
B) 3.3 Pa
C) 11 Pa
D) 15 Pa
E) 28 Pa
Difficulty: M
Section: 17-2
Learning Objective 17.2.7
14. This graph shows the position of an element of air as a function of time as a sound wave passes through it. Which letter corresponds to the amplitude of the wave?
A) A
B) B
C) C
D) D
E) E
Difficulty: E
Section: 17-2
Learning Objective 17.2.8
15. This graph shows the position of an element of air as a function of time as a sound wave passes through it. Which letter corresponds to the period of the wave?
A) A
B) B
C) C
D) D
E) E
Difficulty: E
Section: 17-2
Learning Objective 17.2.8
16. Two small identical speakers are connected (in phase) to the same source. The speakers are 3 m apart and at ear level. An observer stands at X, 4 m in front of one speaker as shown. If the amplitudes are not changed, the sound he hears will be least intense if the wavelength is:
A) 1 m
B) 2 m
C) 3 m
D) 4 m
E) 5 m
Difficulty: M
Section: 17-3
Learning Objective 17.3.1
17. Two small identical speakers are connected (in phase) to the same source. The speakers are 3 m apart and at ear level. An observer stands at X, 4 m in front of one speaker as shown. The sound she hears will be most intense if the wavelength is:
A) 5 m
B) 4 m
C) 3 m
D) 2 m
E) 1 m
Difficulty: M
Section: 17-3
Learning Objective 17.3.1
18. Two sound waves are traveling through the same medium. They have the same amplitude, wavelength, and direction of travel. If the phase difference between them is 7π, the type of interference they exhibit is:
A) fully constructive
B) fully destructive
C) indeterminate
D) partially constructive
E) partially destructive
Difficulty: E
Section: 17-3
Learning Objective 17.3.2
19. Two waves are out of phase by half a wavelength. What is this in radians?
A) π/6
B) π/4
C) π/2
D) π
E) 3π/2
Difficulty: E
Section: 17.3
Learning Objective 17.3.3
20. Two waves are out of phase by half a wavelength. What is this in degrees?
A) 45°
B) 90°
C) 135°
D) 180°
E) 360°
Difficulty: E
Section: 17.3
Learning Objective 17.3.3
21. The standard reference sound level is about:
A) the threshold of human hearing at 1000 Hz
B) the threshold of pain for human hearing at 1000 Hz
C) the level of sound produced when the 1 kg standard mass is dropped 1 m onto a concrete floor
D) the level of normal conversation
E) the level of sound emitted by a standard 60 Hz tuning fork
Difficulty: E
Section: 17-4
Learning Objective 17.4.0
22. A microphone of surface area 2.0 cm2 absorbs 1.1 mW of sound. What is the intensity of sound hitting the microphone?
A) 2.2 x 10-5 W/m2
B) 0.55 W/m2
C) 2.2 W/m2
D) 2.8 W/m2
E) 5.5 W/m2
Difficulty: E
Section: 17.4
Learning Objective 17.4.1
23. The speed of sound in air is 340 m/s, and the density of air is 1.2 kg/m3. If the displacement amplitude of a 440-Hz sound wave is 10 µm, what is the intensity of the wave?
A) 0.16 W/m2
B) 0.32 W/m2
C) 12 W/m2
D) 16 W/m2
E) 32 W/m2
Difficulty: M
Section: 17.4
Learning Objective 17.4.2
24. Consider two imaginary spherical surfaces of different radius, both centered on a point sound source emitting spherical waves. The power transmitted across the larger sphere is ________ the power transmitted across the smaller and the intensity at a point on the larger sphere is ________ the intensity at a point on the smaller.
A) greater than, the same as
B) greater than, greater than
C) greater than, less than
D) the same as, less than
E) the same as, the same as
Difficulty: E
Section: 17-4
Learning Objective 17.4.4
25. The sound intensity 5.0 m from point source is 0.50 W/m2. The power output of the source is:
A) 12.5 W
B) 39 W
C) 79 W
D) 160 W
E) 260 W
Difficulty: M
Section: 17-4
Learning Objective 17.4.4
26. The sound level at a point P is 14 db below the sound level at a point 1.0 m from a point source. Assuming the intensity from a point source drops off like the inverse square of the distance, the distance from the source to point P is:
A) 4.0 cm
B) 20 m
C) 2.0 m
D) 5.0 m
E) 25 m
Difficulty: H
Section: 17-4
Learning Objective 17.4.4
27. The intensity of a certain sound wave is 6 W/cm2. If its intensity is raised by 10 decibels, the new intensity is:
A) 60 W/cm2
B) 6.6 W/cm2
C) 6.06 W/cm2
D) 600 W/cm2
E) 12 W/cm2
Difficulty: E
Section: 17-4
Learning Objective 17.4.5
28. If I0 = 10-12 W/m2, and I = 4.5 x 10-8 W/m2, what is log (I/I0)?
A) 4.5 x 104
B) 18
C) 11
D) 4.7
E) 3.7
Difficulty: E
Section: 17-4
Learning Objective 17.4.6
29. The intensity of sound wave A is 100 times that of sound wave B. Relative to wave B the sound level of wave A is:
A) –2 db
B) +2 db
C) +10 db
D) +20 db
E) +100 db
Difficulty: E
Section: 17-4
Learning Objective 17.4.7
30. If the sound level is increased by 10 db the intensity increases by a factor of:
A) 2
B) 5
C) 10
D) 20
E) 100
Difficulty: E
Section: 17-4
Learning Objective 17.4.7
31. You are listening to an "A" note played on a violin string. Let the subscript "s" refer to the violin string and "a" refer to the air. Then:
A) fs = fa but s a
B) fs = fa and s = a
C) s = a but fs fa
D) s a and fs fa
E) linear density of string = volume density of air
Difficulty: E
Section: 17-5
Learning Objective 17.5.0
32. Two pipes are each open at one end and closed at the other. Pipe A has length L and pipe B has length 2L. Which harmonic of pipe B matches in frequency the fundamental of pipe A?
A) The fundamental
B) The second
C) The third
D) The fourth
E) There are none
Difficulty: M
Section: 17-5
Learning Objective 17.5.0
33. An organ pipe with one end open and the other closed is operating at one of its resonant frequencies. The open and closed ends are respectively:
A) pressure node, pressure node
B) pressure node, displacement node
C) displacement antinode, pressure node
D) displacement node, displacement node
E) pressure antinode, pressure antinode
Difficulty: E
Section: 17-5
Learning Objective 17.5.0
34. The "A" on a trumpet and a clarinet have the same pitch, but the two are clearly distinguishable. Which property is most important in enabling one to distinguish between these two instruments?
A) intensity
B) fundamental frequency
C) displacement amplitude
D) pressure amplitude
E) harmonic content
Difficulty: E
Section: 17-5
Learning Objective 17.5.0
35. Two notes are an octave apart. The ratio of their frequencies is:
A) 8
B) 10
C)
D) 2
E)
Difficulty: E
Section: 17-5
Learning Objective 17.5.0
36. A standing wave in a pipe has nodes that are 1.2 m apart. What is the wavelength of the wave?
A) 0.6 m
B) 1.2 m
C) 1.8 m
D) 2.4 m
E) cannot tell without knowing which harmonic it is
Difficulty: E
Section: 17-5
Learning Objective 17.5.2
37. A tuning fork produces sound waves of wavelength in air. This sound is used to cause resonance in an air column, closed at one end and open at the other. The length of this column CANNOT be:
A) /4
B) 2/4
C) 3/4
D) 5/4
E) 7/4
Difficulty: E
Section: 17-5
Learning Objective 17.5.3
38. A column of argon is open at one end and closed at the other. The shortest length of such a column that will resonate with a 200 Hz tuning fork is 42.5 cm. The speed of sound in argon must be:
A) 85.0 m/s
B) 170 m/s
C) 340 m/s
D) 470 m/s
E) 940 m/s
Difficulty: M
Section: 17-5
Learning Objective 17.5.4
39. A 1024 Hz tuning fork is used to obtain a series of resonance levels in a gas column of variable length, with one end closed and the other open. The length of the column changes by 20 cm from resonance to resonance. From this data, the speed of sound in this gas is:
A) 20 m/s
B) 51 m/s
C) 102 m/s
D) 205 m/s
E) 410 m/s
Difficulty: M
Section: 17-5
Learning Objective 17.5.4
40. A vibrating tuning fork is held over a water column with one end closed and the other open. As the water level is allowed to fall, a loud sound is heard for water levels separated by 17 cm. If the speed of sound in air is 340 m/s, the frequency of the tuning fork is:
A) 58 Hz
B) 500 Hz
C) 1000 Hz
D) 2000 Hz
E) 5800 Hz
Difficulty: M
Section: 17-5
Learning Objective 17.5.4
41. An organ pipe with one end closed and the other open has length L. Its fundamental frequency is proportional to:
A) L
B) 1/L
C) 1/L2
D) L2
E)
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
42. Five organ pipes are described below. Which one has the highest fundamental frequency?
A) A 2.3-m pipe with one end open and the other closed
B) A 3.3-m pipe with one end open and the other closed
C) A 1.6-m pipe with both ends open
D) A 3.0-m pipe with both ends open
E) a pipe in which the displacement nodes are 5 m apart
Difficulty: M
Section: 17-5
Learning Objective 17.5.4
43. If the speed of sound is 340 m/s, the two lowest frequencies of an 0.5 m organ pipe, closed at one end, are approximately:
A) 170 and 340 Hz
B) 170 and 510 Hz
C) 340 and 680 Hz
D) 340 and 1020 Hz
E) 57 and 170 Hz
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
44. The lowest tone produced by a certain organ comes from a 3.0-m pipe with both ends open. If the speed of sound is 340 m/s, the frequency of this tone is approximately:
A) 14 Hz
B) 28 Hz
C) 57 Hz
D) 110 Hz
E) 230 Hz
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
45. The speed of sound in air is 340 m/s. The shortest air column, closed at one end, which will resonate to a 512 Hz tuning fork is approximately:
A) 4.2 cm
B) 8.3 cm
C) 17 cm
D) 33 cm
E) 66 cm
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
46. If the speed of sound is 340 m/s, the shortest pipe, closed at one end, which resonates at 218 Hz is:
A) 39 cm
B) 78 cm
C) 1.6 m
D) 3.1 m
E) 6.2 m
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
47. Organ pipe Y (open at both ends) is twice as long as organ pipe X (open at one end) as shown. The ratio of their fundamental frequencies fX::fY is:
A) 1:1
B) 1:2
C) 2:1
D) 1:4
E) 4:1
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
48. A 200-cm organ pipe with one end open is in resonance with a sound wave of wavelength 270 cm. The pipe is operating in its:
A) fundamental frequency
B) first harmonic
C) second harmonic
D) third harmonic
E) fourth harmonic
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
49. An organ pipe with both ends open is 0.85 m long. Assuming that the speed of sound is 340 m/s, the frequency of the third harmonic of this pipe is:
A) 200 Hz
B) 300 Hz
C) 400 Hz
D) 600 Hz
E) none of these
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
50. The valves of a trumpet and the slide of a trombone are for the purpose of:
A) playing short (staccato) notes
B) tuning the instruments
C) changing the harmonic content
D) changing the length of the air column
E) producing gradations in loudness
Difficulty: E
Section: 17-5
Learning Objective 17.5.4
51. Beats in sound occur when:
A) two waves of the same frequency interfere
B) two waves of slightly different frequency interfere
C) a reflected wave interferes with an incident wave
D) waves travel in two media having slightly different sound velocities
E) source and observer are in relative motion
Difficulty: E
Section: 17-6
Learning Objective 17.6.1
52. To produce beats it is necessary to use two waves:
A) traveling in opposite directions
B) of slightly different frequencies
C) of equal wavelengths
D) of equal amplitudes
E) whose ratio of frequencies is an integer
Difficulty: E
Section: 17-6
Learning Objective 17.6.1
53. In order for two sound waves to produce audible beats, it is essential that the two waves have:
A) the same amplitude
B) the same frequency
C) the same number of overtones
D) slightly different amplitudes
E) slightly different frequencies
Difficulty: E
Section: 17-6
Learning Objective 17.6.1
54. The largest number of beats per second will be heard from which pair of tuning forks?
A) 200 and 201 Hz
B) 256 and 260 Hz
C) 534 and 540 Hz
D) 763 and 774 Hz
E) 8420 and 8422 Hz
Difficulty: E
Section: 17-6
Learning Objective 17.6.3
55. When listening to tuning forks of frequency 256 Hz and 260 Hz, one hears the following number of beats per second:
A) 0
B) 2
C) 4
D) 8
E) 258
Difficulty: E
Section: 17-6
Learning Objective 17.6.3
56. Two identical tuning forks vibrate at 256 Hz. One of them is then loaded with a drop of wax, after which 6 beats per second are heard. The frequency of the loaded tuning fork is:
A) 250 Hz
B) 253 Hz
C) 256 Hz
D) 259 Hz
E) 262 Hz
Difficulty: E
Section: 17-6
Learning Objective 17.6.3
A) that before tightening A had a higher frequency than B, but after tightening, B has a higher frequency than A
B) that before tightening B had a higher frequency than A, but after tightening, A has a higher frequency than B
C) that before and after tightening A has a higher frequency than B
D) that before and after tightening B has a higher frequency than A
E) none of the above
Difficulty: M
Section: 17-6
Learning Objective 17.6.3
58. Two stationary tuning forks (350 and 352 Hz) are struck simultaneously. The resulting sound is observed to:
A) beat with a frequency of 2 beats/s
B) beat with a frequency of 351 beats/s
C) be loud but not beat
D) be Doppler shifted by 2 Hz
E) have a frequency of 702 Hz
Difficulty: E
Section: 17-6
Learning Objective 17.6.3
59. The rise in pitch of an approaching siren is an apparent increase in its:
A) speed
B) amplitude
C) frequency
D) wavelength
E) number of overtones
Difficulty: E
Section: 17-7
Learning Objective 17.7.1
60. The Doppler shift formula for the frequency detected is
where f ' is the frequency emitted, v is the speed of sound, vD is the speed of the detector, and vs is the speed of the source. Suppose the source is traveling at 5 m/s away from the detector, the detector is traveling at 7 m/s toward the source, and there is a 3 m/s wind blowing from the source toward the detector. The values that should be substituted into the Doppler shift equation are:
A) vD = 7 m/s and vs = 5 m/s
B) vD = 10 m/s and vs = 8 m/s
C) vD = 4 m/s and vs = 2 m/s
D) vD = 10 m/s and vs = 2 m/s
E) vD = 4 m/s and vs = 8 m/s
Difficulty: M
Section: 17-7
Learning Objective 17.7.2
61. A stationary source generates 5.0 Hz water waves whose speed is 2.0 m/s. A boat is approaching the source at 1.0 m/s. The frequency of these waves, as observed by a person in the boat, is:
A) 2.5 Hz
B) 5.0 Hz
C) 7.5 Hz
D) 15 Hz
E) 30 Hz
Difficulty: E
Section: 17-7
Learning Objective 17.7.3
62. A stationary source S generates circular outgoing waves on a lake. The wave speed is 5.0 m/s and the crest-to-crest distance is 2.0 m. A person in a motor boat heads directly toward S at 3.0 m/s. To this person, the frequency of these waves is:
A) 1.0 Hz
B) 1.5 Hz
C) 2.0 Hz
D) 4.0 Hz
E) 8.0 Hz
Difficulty: M
Section: 17-7
Learning Objective 17.7.3
63. A stationary source emits a sound wave of frequency f. If it were possible for a man to travel toward the source at the speed of sound, he would observe the emitted sound to have a frequency of:
A) 0
B) f/2
C) 2f/3
D) 2f
E) infinity
Difficulty: E
Section: 17-7
Learning Objective 17.7.3
64. A source emits sound with a frequency of 1000 Hz. Both it and an observer are moving in the same direction with the same speed, 100 m/s. If the speed of sound is 340 m/s, the observer hears sound with a frequency of:
A) 290 Hz
B) 540 Hz
C) 1000 Hz
D) 1800 Hz
E) 3400 Hz
Difficulty: E
Section: 17-7
Learning Objective 17.7.3
65. A source emits sound with a frequency of 1000 Hz. It and an observer are moving toward each other, each with a speed of 100 m/s. If the speed of sound is 340 m/s, the observer hears sound with a frequency of:
A) 290 Hz
B) 540 Hz
C) 1000 Hz
D) 1800 Hz
E) 3400 Hz
Difficulty: E
Section: 17-7
Learning Objective 17.7.3
66. A source emits sound with a frequency of 1000 Hz. It is moving at 20 m/s toward a stationary reflecting wall. If the speed of sound is 340 m/s an observer at rest directly behind the source hears a beat frequency of:
A) 3.0 Hz
B) 55 Hz
C) 63 Hz
D) 114 Hz
E) 118 Hz
Difficulty: M
Section: 17-7
Learning Objective 17.7.3
67. In each of the following two situations a source emits sound with a frequency of 1000 Hz. In situation I the source is moving at 100 m/s toward an observer at rest. In situation II the observer is moving at 100 m/s toward the source, which is stationary. The speed of sound is 340 m/s. The frequencies heard by the observers in the two situations are:
A) I: 1417 Hz; II: 1294 Hz
B) I: 1417 Hz; II: 1417 Hz
C) I: 1294 Hz; II: 1294 Hz
D) I: 773 Hz; II: 706 Hz
E) I: 773 Hz; II: 773 Hz
Difficulty: M
Section: 17-7
Learning Objective 17.7.3
68. The diagram shows four situations in which a source of sound S and a detector D are either moving or stationary. The arrows indicate the directions of motion. The speeds (when not zero) are all the same. (Note that the detector in situation 3 is stationary). Rank the situations according to the apparent frequency of the source, lowest to highest.
A) 1, 2, 3, 4
B) 4, 3, 2, 1
C) 1, 3, 4, 2
D) 2, 1, 4, 3
E) None of the above
Difficulty: E
Section: 17-7
Learning Objective 17.7.4
69. A plane produces a sonic boom only when:
A) its speed changes from being slower than the speed of sound to being faster than the speed of sound
B) it emits sound waves of high frequency
C) it flies at high altitudes
D) it flies on a curved path
E) it flies faster than the speed of sound
Difficulty: E
Section: 17-8
Learning Objective 17.8.0
70. If the speed of sound is 340 m/s a plane flying at 400 m/s has a Mach number of:
A) 0.85
B) 1.2
C) 1.4
D) 1.7
E) 400
Difficulty: E
Section: 17-8
Learning Objective 17.8.2
71. If the speed of sound is 340 m/s a plane flying at 400 m/s creates a conical shock wave with an apex half angle of:
A) 0° (no shock wave)
B) 32
C) 40
D) 50
E) 58
Difficulty: M
Section: 17-8
Learning Objective 17.8.3
72. The speed of sound is 340 m/s. A plane flies horizontally at an altitude of 10,000 m and a speed of 400 m/s. When an observer on the ground hears the sonic boom the horizontal distance from the point on its path directly above the observer to the plane is (assume the speed of sound does not change with altitude):
A) 5800 m
B) 6100 m
C) 8400 m
D) 12,000 m
E) 16,000 m
Difficulty: M
Section: 17-8
Learning Objective 17.8.3