TERMS
Branch of physics pertaining to sound.
ACOUSTICS
How to find frequency once knowing wavelength and speed.
A sound wave has a wavelength of 4.0 m. The distance between the center of a compression and the center of the next adjacent rarefaction is…
2.0 m
The speed of sound in air is dependent on these two properties.
TEMPERATURE & HUMIDITY
Frequencies below 20 Hz according to humans.
INFRASOUND
Frequency pattern in harmonics
fn = n*f1
A vibrating object with a frequency of 300 Hz produces sound through air at 400 m/s. What is the distance between the adjacent compressions in the sound?
1.3 m
(w = v/f, 400 / 300)
Three main parts to the ear.
OUTER
MIDDLE
INNER
Periodic and repeating fluctuations heard in the intensity of a sound when two waves of very similar frequencies interfere with one another.
BEATS
Finding intensity
Intensity = Energy/(Time*Area)
Intensity = Power/Area
A stretched string vibrates with a fundamental frequency of 200. Hz. The frequency of the second harmonic is…
400 Hz
(f2 = 2*f1)
Term describing the faintest sound detectable.
THRESHOLD OF HEARING
Sound waves can impinge upon a detecting device due to fluctuations in this type of wave.
PRESSURE
Speed of sound in air.
v = 331 m/s + (0.6 m/s/C)*T
Find the speed of sound in air that is 12°C.
338 m/s
(331 + .6*12)
What decibel level will instantly perforate your eardrum?
160 dB
Amount of energy transported past a given area of the medium per unit of time.
INTENSITY (OF SOUND WAVE)
What you know about the harmonics of closed-end air columns.
ODD NUMBERED ONLY
A stretched phone cord has a length of 2.4 m and a mass of 1.8 kg. The tension in the phone cord is 2.5 N, find the vibrational speed in the cord.
1.8 m/s
[mass / length = 1.8 kg / 2.4 m = 0.75 kg/m, v = SQRT(Ftens/mu) = SQRT(2.5N/.75)]
Frequency range that humans can perceive.
20 - 20,000 Hz