Question

A source of wave produces 32 compressions and 32 rarefactions in 0.4 s. Calculate the frequency of the wave.

Answer 1

Answer:

Crest is a point of a wave where the displacement of swaying particles become maximum and Trough is a point of wave where displacement of swaying particles is minimum. The wave length is the distance between two closest crests or the distance between the two closest troughs. As we see 2 crests are related with one wavelength and 2 troughs are related with one wavelength. So if 32 crests and 32 there it means there are 32wavelengths.

If 32wavelengths produced in 0.4 seconds, then, 32m/0.4 s wavelengths are produced in 1 second. Wavelengths produced per second is the frequency of the specific wave.

So the frequency of the sound is = 32m/0.4 s = 80 Hz.