WAVE REVIEW
Low pressure region of wave where particles are more spread out.
RAREFACTION
Particular frequency or set of frequencies that an object tends to vibrate at.
NATURAL FREQUENCY
An open-end air column has a second harmonic frequency of 880 Hz. The speed of sound in it is 350 m/s. What is the frequency of the first harmonic?
440 Hz
(880 / 2)
For a lower frequency from an air column, the column will need to be…
LONGER
Altered perception of a wave due to the speed of the source moving slower than the speed of the waves.
DOPPLER EFFECT
Lowest frequency produced by any instrument.
FUNDAMENTAL FREQUENCY
What is the fundamental frequency of a 62.5-cm chime at 40°C?
284 Hz (354 m/s / 1.25 m since wavelength is 2*column)
If a tuning fork is sounding at 252 Hz and another is sounding at 257 Hz, what beat frequency will be heard?
5 Hz
Wave type associated with harmonics.
STANDING WAVES
Rate at which the volume is heard to be oscillating from high to low volume.
BEAT FREQUENCY
A closed end column has a natural frequency of 3500 Hz. If the speed of the waves in it is 350 m/s, what is the length of the column?
2.5 cm
(WL = v/f = 350 m/s / 3500 Hz)
What kind of wavelength would be associated with a high pitched sound?
LOW/SHORT
Change in direction of sound waves as they pass around an opening or barrier in their path.
DIFFRACTION
Two musical notes that have a frequency ratio of 2:1 are said to be separated by one of these.
OCTAVE
A guitar string with mass of 32.4 g and length of 1.12 m is pulled to a tension of 621 N. If the full length is used to produce the first harmonic, what frequency results?
65.4 Hz
(f = v/WL = 146.5 m/s / 2.24 m)
The number ratios of resonant frequencies in a musical instrument are always…
WHOLE NUMBERS
Effect of wave speed being altered due to passing from one medium into another.
BOUNDARY BEHAVIOR
Tendency of an object to force another adjoining or interconnected object into vibrational motion.
FORCED VIBRATION/RESONANCE
A closed-end air column with length of 135 cm is sounding at 25°C. What is the frequency of the third harmonic?
192 Hz
(speed of sound at 25C is 346 m/s, f1 = v/WL = 346 m/s / 5.40 m = 64.0Hz, f3 = 3*f1 = 3*64.0 Hz)
Intense sounds are usually perceived by humans as being at what level?
LOUD