Sound, Doppler Flashcards
What medium does sound travel fastest in?
Solid
Speed of sound in air at RT
340 m/s
General rule regarding speed of sound with respect to KE and molecular inertia
V sim to sq root Restoring force/Molecular KE/Molecular inertia
Sound is a ___ wave
longitudinal
Equation for intensity of sound
I= Energy/(Area)(Time) or Power/Area
Doppler effect standard equation
fL= ((v+/-vL)/(v+/-Vs))fs
Bat emits ultrasonic squeak in direction of an insect and notices that the reflected sound is of a lower freq than emitted pulse. What explains this frequency shift?
Either the bat or insect is moving away from the other.
Standing wave
Produced from waves traveling in opposite directions along a string that combine to produce a wave disturbance, which appears to oscillate up and down without propagating
What is the beat frequency created upon interference with the third harmonic with the fifth harmonic of waves on a fixed string
Frequency of second harmonic
Beat freq= abs value of difference between two freqs
Fundamental frequency equation
f1= fn- f(n-1)
Open pipe equations
L=wavelength/2
f= v/2L
Vibrate at all multiples of fundamental frequency
fn= n(v/2L)
Closed pipe equations
L= wavelength/ 4
f=v/4L
Can only vibrate at odd multiples of fundamental freq
fn= n (v/4L) where n= 1,3,5
Does warm or cool air produce higher frequency sound waves?
Warm. Gases travel faster in warm air, so speed on sound wave will be faster
