A musical tone of frequency f 1000 Hz is produced by a sour

A musical tone of frequency f = 1000 Hz is produced by a source S. The sound impinges on a wall with two slits separated by a distance d = 3 m. The Speed of sound in air is 350 m/s. In parts (a) and (b) the source is taken to be at source. What is the wave length of the sound measured by an observer at point A a distance 100 m from the wall? At what distance y will a listener B hear practically no sound?

Solution

Here,

f = 1000 Hz

wavelength = speed of sound/f

wavelength = 350/1000 = 0.350 m

D = 100 m

part a) the wave length of the sound measured is 0.350 m

part b)

for no sound

y = 0.5 * wavelength * d/D

y = 0.5 * 0.350 * 3/100

y = 5.25 *10^-3 m

the distance y for no sound is 5.25 *10^-3 m

part c)

at y for a maxima to be present

new wavelength = 2 * wavelength

hence , speed of source = speed of sound wave

speed of source = 350 m/s

the speed of soruce must be 350 m/s towards the wall