Question

two point sound source A and B each of power 25 pie W and frequency 850 Hz are 1 m apart. the sources are in phase :
a)determine the phase difference between the waves emitting from A and B received by detector D.

Answer 1

The phase difference is given by :

(2 π× distance difference) ÷ lambda where lambda is the sound wavelength.

We need to get the wavelength of the sound waves.

Lambda = V/f where V is the velocity of sound in air and f the frequency of the sound.

Velocity of sound in air = 331.2 m/s

F =850Hz

Lambda =331.2/850=0.38965m

The power of these waves is 25 π from the formulae it means we have 25/2 =12.5 total phase difference.

Substituting in the formula we have:

(2 π × 1)/0.38965 = 16.125

Since we have 12.5 of these, the total phase difference is:

12.5 × 16.125 = 201.5625