Multiple Choice
14.1 Speed of Sound, Frequency, and Wavelength
What properties does a loud, shrill whistle have?
- high amplitude, high frequency
- high amplitude, low frequency
- low amplitude, high frequency
- low amplitude, low frequency
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5960\,\text{m}/\text{s}
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1540\,\text{m}/\text{s}
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331\,\text{m}/\text{s}
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1480\,\text{m}/\text{s}

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About 225.
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About 450.
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Slightly over 500.
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Slightly over 1,000.
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The amplitude of a sound wave decreases with distance from its source, because the frequency of the sound wave decreases.
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The amplitude of a sound wave decreases with distance from its source, because the speed of the sound wave decreases.
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The amplitude of a sound wave decreases with distance from its source, because the wavelength of the sound wave increases.
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The amplitude of a sound wave decreases with distance from its source, because the energy of the wave is spread over a larger and larger area.
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No, there is no relationship that exists between the speed of sound and elasticity of the medium.
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Yes. When particles are more easily compressed in a medium, sound does not travel as quickly through the medium.
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Yes. When the particles in a medium do not compress much, sound does not travel as quickly through the medium.
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No, the elasticity of a medium affects frequency and wavelength, not wave speed.
14.2 Sound Intensity and Sound Level
Which of the following terms is a useful quantity to describe the loudness of a sound?
- intensity
- frequency
- pitch
- wavelength
What is the unit of sound intensity level?
- decibels
- hertz
- watts
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5\,\text{dB}
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6\,\text{dB}
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7\,\text{dB}
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100\,\text{Hz}
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10\,\text{Hz}
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5\,\text{Hz}
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1\,\text{Hz}
Why is I0 chosen as the reference for sound intensity?
- Because, it is the highest intensity of sound a person with normal hearing can perceive at a frequency of 100 Hz.
- Because, it is the lowest intensity of sound a person with normal hearing can perceive at a frequency of 100 Hz.
- Because, it is the highest intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz.
- Because, it is the lowest intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz.
14.3 Doppler Effect and Sonic Booms
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The source and the observer are moving towards each other.
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The observer is moving toward the source.
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The source is moving away from the observer.
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Neither the source nor the observer is moving relative to one another.
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speed of the source
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frequency of source
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amplitude of source
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distance of observer from the source
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303\,\text{Hz}
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259\,\text{Hz}
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201\,\text{Hz}
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146\,\text{Hz}
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The frequency will become lower.
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The frequency will become higher.
14.4 Sound Interference and Resonance
Observation of which phenomenon can be considered proof that something is a wave?
- interference
- noise
- reflection
- conduction
Which of the resonant frequencies has the greatest amplitude?
- The first harmonic
- The second harmonic
- The first overtone
- The second overtone
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3\,\text{v}/2\,\text{L}
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2\,\text{v}/\text{L}
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\text{v}/\text{L}
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\text{v}/2\,\text{L}
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640\,\text{Hz}
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320\,\text{Hz}
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20\,\text{Hz}
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40\,\text{Hz}