calculate the frequency of a sound wave?

Question

Calculate the frequency of a sound wave in helium if its displacement amplitude in helium is 3.9 *10^-10 m and the pressure amplitude is 8.8 *10^-5 N/m^2. The density of helium is 0.48 kg/m^3 and the speed of sound in helium is 291. 6 m/s. Answer in Hz.

Answer 1

This page gives you all the data (i.e. the equations) you need:

http://en.wikipedia.org/wiki/Particle_displacement

from the speed of sound and the density you can compute the characteristic impedance, Z0

the frequency is a function of the displacement amplitude, the pressure amplitude, and the characteristic impedance.