Acoustics Answers

A string of natural length L extends to a new length L' under tensile force F. If Hooke’S law applies, the work done in stretching the spring is ------------
1/2FL
1/2FL'
1/2 F(L-L')
F(L-L')

In the wave equation, it states that wavelength = velocity of the wave ÷ frequency. Or is it the constant velocity of light 299,792,458 divided by the frequency. And if it is the velocity of the wave ÷ frequency, how do I find the velocity of the wave without knowing wavelength? All I know is frequency and the length of the string that is being plucked.

what is the mass of chair inside a classroom where g=9.8 m/s2 if it weights 300 N? what it is weight if it were on the surface of the moon

A team of geophysicists is standing on the ground. Beneath their feet, at an unknown distance, is the ceiling of a cavern. Its floor is a distance h below this ceiling. To measure h, the team places microphones on the ground. At t = 0 s, a sound pulse is sent straight downward through the ground and into the cavern. When this pulse reaches the ceiling of the cavern, one part of it is reflected back toward the microphones, and a second part continues downward, eventually to be reflected from the cavern floor. The sound reflected from the cavern ceiling reaches the microphones at t = 0.0245 s, and the sound reflected from the cavern floor arrives at t = 0.0437 s. The cavern is presumed to be filled with air at a temperature at 9 degrees Celsius. Assuming that sir behaves like an ideal gas, what is the height h of the cavern?

A bat flies at a steady speed of 4 m/s emitting a sound of f = 90000 Hz. It is flying horizontally towards a vertical wall. What is the frequency of the reflected sound as detected by the bat?
(Take velocity of sound in air as 330 m/s).

if the frequency of the tuning fork is 400 Hz and the speed of sound in air is 350 m/s .find how far sound travels while tuning fork makes 6 vibrations.

a sonar station picks up a return signal after 3seconds. how far away is the object?(speed of sound in water=1440m/s)

A bat flies at a steady rate of 4 m/s emitting 90 kHz sound wave and is flying towards a wall.It detects a reflected signal at s frequency………….kHz.Given speed of sound=340m/s.
a)90.1 b)92.1 c)91.1 d)93.1

A source and an observer move away from each other with a velocity of 10m/s with respect to ground.If the observer finds the frequency of sound coming from the source as 1950 Hz,then actual frequency of the source is (velocity of sound in airt =340m/s):a)2486Hz b)2132Hz c)2068Hz d)1950Hz.

An organ pipe enclosed at one end has fundamental frequency of 1500 Hz. The maximum number of overtones generated by this pipe which a normal person can hear is : a) 6 b)11 c)9 d)13.