Question

"a horn emits a frequency of 1000 HZ. A 14 m/s wind is blowing toward a listener. What is the frequency of the sound heard by the listener

Answer 1

`f_L = 1000 Hz`

Step-by-step explanation:

given,

speed of wind, = 14 m/s

frequency of horn,f_s = 1000 Hz

speed of sound,V = 344 m/s

frequency heard by the listener

using Doppler effect

`f_L = (v+v_L)/(v+v_s)f_s`

f_L is the frequency of the sound heard by the listener

f_s is the frequency of sound emitted by the listener

V is the speed of sound

v_L is the speed of listener

v_s is the speed of source

now,

considering the frame of reference in which wind is at rest now, both listener and the source will be moving at 14 m/s

`f_L = (v+14)/(v+14)* 1000`

now on solving we will get

`f_L = 1000 Hz`

hence, the frequency heard by the listener is equal to 1000 Hz