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
- The amplitude of a sound wave decreases with distance from its source, because the frequency of the sound wave decreases.
- The amplitude of a sound wave decreases with distance from its source, because the speed of the sound wave decreases.
- The amplitude of a sound wave decreases with distance from its source, because the wavelength of the sound wave increases.
- 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.
- No, there is no relationship that exists between the speed of sound and elasticity of the medium.
- Yes. When particles are more easily compressed in a medium, sound does not travel as quickly through the medium.
- Yes. When the particles in a medium do not compress much, sound does not travel as quickly through the medium.
- 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
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
- The source and the observer are moving towards each other.
- The observer is moving toward the source.
- The source is moving away from the observer.
- Neither the source nor the observer is moving relative to one another.
- speed of the source
- frequency of source
- amplitude of source
- distance of observer from the source
- The frequency will become lower.
- 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