# Shared Flashcard Set

## Details

Musical Acoustics
Unit I Test
61
Physics
09/17/2011

Term
 Longitudinal Waves
Definition
 Move the direction of the propagation of the wave
Term
 Transverse Waves
Definition
 Move Perpendicular to the propagation of the wave
Term
 Sound
Definition
 Longitudinal pressure/displacement wave
Term
 Normal frequency of sound?
Definition
 20 Hz to 20 kHz (20,000)
Term
 Pressure
Definition
 Force / area
Term
 Unit for Pressure
Definition
 Pascal or (Newton/Meter)
Term
 Sound requires what to propagate?
Definition
 A medium, such as air, water, solid, etc.
Term
 The velocity of sound in air at room temp. is?
Definition
 343 m/s
Term
 Wave
Definition
 A change or a disturbance that propagates from one place to another
Term
Definition
 Not sound waves. Electro-magnetic waves.
Term
Definition
 Not sound waves. Electro-magnetic waves.
Term
 Velocity of a wave?
Definition
 Distance apoint on the wave travels divided by the time it takes to move.v=d/t
Term
 Sound is non-dispersive, which means it's velocity is:
Definition
 independent from it's frequency
Term
 Velocity of air at any temp
Definition
 v=343m/s + 0.6(T-20 C)
Term
 Frequency
Definition
 Number of times something happens in a second (Hz)f=1/p
Term
 frequency x wavelength = ?
Definition
 velocity
Term
 Period
Definition
 time it takes to make one cycle, oscillation or pulseP=1/f
Term
 wavelength notated with:
Definition
 upside down squiggly v thing
Term
 Sound travels faster in -- air than in --.
Definition
 Warm, Cold
Term
 Standard atmospheric pressure
Definition
 101 kPa
Term
 Simple Harmonic Oscillator
Definition
 device that oscillates at one frequency, determined by the spring constant K and the mass m of the system
Term
 Equation for natural frequency of a Simple Harmonic Oscillator
Definition
 f= 1/(2pie) x √(k/m)
Term
 Hook's Law
Definition
 F= -k * x
Term
 The number of normal or natural modes of vibration of an oscillator is equal to:
Definition
 The number of simple harmonic oscillators that comprise that complex oscillator
Term
 A microphone works by:
Definition
 converting pressure fluctuations into electrical signals
Term
 An oscilloscope displays
Definition
 electrical signals versus time
Term
 The term sine wave describes anything that:
Definition
 varies with time or position
Term
 A simple harmonic oscillator moves like a sine wave. It's motion is called:
Definition
 Sinusoidal
Term
 Complex sounds can be produced from:
Definition
 Simple sounds
Term
 Fourier Analysis
Definition
 Breaking waveforms down into simple sine waves
Term
 The lowest frequency component of a wave is equal to
Definition
 1/P-repeat, the reciprocal of the repeat period P-repeat
Term
 Fourier Synthesis
Definition
 Building waveforms up from simple sine waves
Term
 A Fourier Spectrum is the:
Definition
 recipe for building the waveform
Term
 The lowest (or fundamental) frequency f1 of the components of a waveform is equal to:
Definition
 1/P(repeat)
Term
 A harmonic series is:
Definition
 a Fourier Frequency Spectrum in which the frequency of each of the components is an integral multiple of the fundamental frequencyf1=1f1, f2=2f2, f3=3f3, ect
Term
 Harmonic implies:
Definition
 an integer ration of frequency
Term
 Amplitude
Definition
 amount or size of a component wave
Term
 frequency
Definition
 number of oscillations per second
Term
 Phase
Definition
 the relative starting point of a component wave
Term
 Wave form is determined by these two things:
Definition
 Frequency spectrum and phase spectrum
Term
 Ohms' Law for acoustics
Definition
 Humans cannot directly sense the phase of a sound wave
Term
 Correlation w/ musical characteristics:AmplitudeFrequencyWaveformContour
Definition
 LoudnessPitchTimbreRhythm
Term
 Pitch is based on:
Definition
 the ratio of frequencies
Term
 A given frequency ration is called an
Definition
 interval
Term
 An octave is the pitch interval that corresponds to a ration of:
Definition
 f2/f1= 2/1
Term
 Period is the time from
Definition
 one point on a wave to a corresponding point on the next
Term
 Period is the time from
Definition
 one point on a wave to a corresponding point on the next
Term
 frequency
Definition
 1/period
Term
 phase is the:
Definition
 shift (measured in fraction of a cycle) for a wave relative to a time standard
Term
 Mechanical energy is carried in
Definition
 sound
Term
 Work=
Definition
 Force x Distance (in Joules or Newton meters)
Term
 Heat is a form of
Definition
 energy
Term
 Power is the
Definition
 rate of energy dissipation or radiation
Term
 P=
Definition
 W/t (In Watts or Joules/sec)
Term
 Intensity is:
Definition
 Power/Area
Term
 higher frequencies tend to -- more rapidly than do lower frequencies
Definition
 Damp
Term
 Transient
Definition
 A short lived burst of energy in a system
Term
 Transients occur because
Definition
 radiation and friction damp the various harmonics differently
Term
 Resonance is the phenomenon of
Definition
 sympathetic vibration at a natural frequency with energy supplied from an outside source
Term
 micro
Definition
 -6
Term
 Mega
Definition
 +6
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