Short Answer
14.1 Speed of Sound, Frequency, and Wavelength
What component of a longitudinal sound wave is analogous to a trough of a transverse wave?
- compression
- rarefaction
- node
- antinode
What is the frequency of a sound wave as perceived by the human ear?
- timbre
- loudness
- intensity
- pitch
What properties of a solid determine the speed of sound traveling through it?
- mass and density
- rigidity and density
- volume and density
- shape and rigidity
Does the density of a medium affect the speed of sound?
- No
- Yes
Does a bat make use of the properties of sound waves to locate its prey?
- No
- Yes
Do the properties of a sound wave change when it travels from one medium to another?
- No
- Yes
14.2 Sound Intensity and Sound Level
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The sound from the passing car’s stereo has a higher amplitude and hence higher intensity compared to the intensity of the sound coming from the person next to you. The higher intensity corresponds to greater loudness, so the first sound dominates the second.
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The sound from the passing car’s stereo has a higher amplitude and hence lower intensity compared to the intensity of the sound coming from the person next to you. The lower intensity corresponds to greater loudness, so the first sound dominates the second.
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The sound from the passing car’s stereo has a higher frequency and hence higher intensity compared to the intensity of the sound coming from the person next to you. The higher frequency corresponds to greater loudness so the first sound dominates the second.
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The sound from the passing car’s stereo has a lower frequency and hence higher intensity compared to the intensity of the sound coming from the person next to you. The lower frequency corresponds to greater loudness, so the first sound dominates the second.
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The intensity is inversely proportional to the power transmitted by the wave, for a constant area.
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The intensity is inversely proportional to the square of the power transmitted by the wave, for a constant area. I=\frac{1}{P^2}
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The intensity is directly proportional to the square of the power transmitted by the wave, for a constant area. I = \text{P}^2
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The intensity is directly proportional to the power transmitted by the wave, for a constant area. I=\frac{P}{A}
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Yes, \text{I} is the sound intensity in watts per meter squared in the equation, \beta (\text{dB}) = 10\log_{10}\left(\frac{I}{I_0}\right).
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I is the sound illuminance and its \text{SI} unit is lumen per meter squared.
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I is the sound intensity and its \text{SI} unit is watts per meter cubed.
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I is the sound intensity and its \text{SI} unit is watts per meter squared.
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The upper limit of human hearing is 100 decibels, i.e. \beta = 100\,\text{dB}. For \beta = 100\,\text{dB}, I_0 = 10^{-12}\,\text{W}/\text{m}^2.
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The lower threshold of human hearing is 10 decibels, i.e. \beta = 10\,\text{dB}. For \beta = 10\,\text{dB}, I_0=10^{-12}\,\text{W}/\text{m}^{2}
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The upper limit of human hearing is 10 decibels, i.e. \beta = 10\,\text{dB}. For \beta = 10\,\text{dB}, I_0 = 10^{-12}\,\text{W}/\text{m}^2
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The lower threshold of human hearing is 0 decibels, i.e., \beta = 0\,\text{dB}. For \beta = 0\,\text{dB}, I_0 = 10^{-12}\,\text{W}/\text{m}^{2}
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I=1.6\times10^{-6}\,\text{W/m}^2
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I=82\times10^{-12}\,\text{W/m}^2
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I=8.2\times10^{-12}\,\text{W/m}^2
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I=1.6\times10^{-4}\,\text{W/m}^2
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0.734\,\text{Pa}
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3.67\,\text{Pa}
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0.135\,\text{Pa}
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0.367\,\text{Pa}
Which nerve carries auditory information to the brain?
- buccal nerve
- peroneal nerve
- cochlear nerve
- mandibular nerve
-
Smaller instruments produce sounds with shorter wavelengths, and thus higher frequencies.
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Smaller instruments produce longer wavelength, and thus higher amplitude, sounds.
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Smaller instruments produce lower amplitude, and thus longer wavelength sounds.
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Smaller instruments produce higher amplitude, and thus lower frequency, sounds.
14.3 Doppler Effect and Sonic Booms
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The frequency will become lower.
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The frequency will be doubled.
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The frequency will be tripled.
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The frequency will become higher.
True or false—The Doppler effect also occurs with waves other than sound waves.
- False
- True
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The sound will become more high-pitched.
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The sound will become more low-pitched.
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The pitch of the sound will not change.
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No, a sonic boom is created only when the source exceeds the speed of sound.
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Yes, sonic booms continue to be created when an object is traveling at supersonic speeds.
-
f_s=401\,\text{Hz or}\,f_s=315\,\text{Hz}
-
f_s=385\,\text{Hz or}\,f_s=419\,\text{Hz}
-
f_s = 415\,\text{Hz or}\,f_s = 366\,\text{Hz}
-
f_s=425\,\text{Hz}\; \text{or}\,f_s=377\,\text{Hz}
What is the frequency of a stationary sound source if you hear it at 1200.0 Hz while moving towards it at a speed of 50.0 m/s? (Assume speed of sound to be 331 m/s.)
- 1410 Hz
- 1380 Hz
- 1020 Hz
- 1042 Hz
14.4 Sound Interference and Resonance
-
It is the average of the frequencies of the two original waves that were superimposed.
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It is the difference between the frequencies of the two original waves that were superimposed.
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It is the product of the frequencies of the two original waves that were superimposed.
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It is the sum of the frequencies of the two original waves that were superimposed.
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No, beats can be produced only by resonance.
-
Yes, beats can be produced by superimposition of any two waves having slightly different frequencies.
How is human speech produced?
- Human speech is produced by shaping the cavity formed by the throat and mouth, the vibration of vocal cords, and using the tongue to adjust the fundamental frequency and combination of overtones.
- Human speech is produced by shaping the cavity formed by the throat and mouth into a closed pipe and using tongue to adjust the fundamental frequency and combination of overtones.
- Human speech is produced only by the vibrations of the tongue.
- Human speech is produced by elongating the vocal cords.
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2 nodes and 3 antinodes or 2 antinodes and 3 nodes.
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2 nodes and 2 antinodes or 3 antinodes and 3 nodes.
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3 nodes and 3 antinodes or 2 antinodes and 2 nodes.
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6 nodes and 4 antinodes or 6 antinodes and 4 nodes.
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second overtone frequency
-
first overtone frequency
-
fundamental frequency
-
third overtone frequency
-
240\,\text{cm}
-
180\,\text{cm}
-
60\,\text{cm}
-
120\,\text{cm}
-
7520\,\text{Hz}
-
1510\,\text{Hz}
-
376\,\text{Hz}
-
1880\,\text{Hz}
-
690\,\text{Hz}
-
470\,\text{Hz}
-
110\,\text{Hz}
-
230\,\text{Hz}