Waves
The highest point on a sine wave is called this
Crest
What units are used to measure perceived loudness?
Decibels
Does the Doppler effect occur with all waves or only sound waves?
All waves
Define "fundamental frequency"
The lowest possible frequency of a standing wave for a particular system (string, pipe, etc.)
The region of a sound wave in which air particles are pushed very close together is called a ___________
Compression
Sound waves are ___________ waves
Longitudinal
Intensity is the rate at which ___________ flows through a unit area perpendicular to the direction of wave motion
Energy
If the length of a string is doubled, how does the wavelength of the fundamental frequency change?
The wavelength of the fundamental frequency is doubled
State the first three harmonics of a string fixed at both ends given the fundamental frequency 50 Hz
1st harmonic: 50 Hz
2nd harmonic: 100 Hz
3rd harmonic: 150 Hz
Generally, sound travels fastest through this state of matter
Solids
A sine waveform can be used to represent a sound wave. What do the crests on this waveform represent?
Compressions
What units are used to measure intensity?
W/m^2 (watts per square meter)
When the frequency of a sound wave increases, the perceived pitch of the sound __________.
Increases
Why does an oboe sound different from a trumpet?
They have different harmonics at different intensities
Describe the difference between forced vibration and resonance
Resonance specifically occurs when the frequency of the force being applied matches the natural frequency of the object and results in a greatly increased amplitude; forced vibration occurs anytime energy is transferred from one vibrating object to another regardless of natural frequency and results in a smaller amplitude.
A sine waveform can be used to represent a sound wave. What do the troughs on this waveform represent?
Rarefactions
The relationship between loudness and intensity is ______________.
Logarithmic
As an ambulance with a siren drives away from you, the perceived pitch of its siren _____________
Decreases
State the first three harmonics in a pipe with two open ends given the fundamental frequency 200 Hz.
1st harmonic: 200 Hz
2nd harmonic: 400 Hz
3rd harmonic: 600 Hz
The distance between wave fronts of plane waves corresponds to the _________ of a sound wave
Wavelength
At a long distance from their source, wave fronts are perceived as this
Plane waves
If a sound's loudness increases by 10 dB, how much has the sound's intensity increased?
The intensity has been multiplied by 10
If the length of a string is doubled, how does the fundamental frequency of the string change?
The fundamental frequency of the string is halved
State the first three harmonics of a pipe with one open end given the fundamental frequency 150 Hz
1st harmonic: 150 Hz
3rd harmonic: 450 Hz
5th harmonic: 750 Hz
Two musicians tune their instruments so their frequencies are closer together, but not quite the same. Does the number of beats per second increase or decrease as they do this?
Decrease