A car is moving along x-axis with a velocity v=20 m/s. it sounds a whistle of frequency 660 Hz. If the speed of sound is 340 m/s, the apparent frequency heard by the observer O (shown in the figure) is [image:15_image1.jpeg]

Question

Dr. Abubacker · Accepted Answer

(a) $n^{'} = \frac{v}{v - v_{s}\cos{60{^\circ}}}n$
Here,
v=340, $v_{s} = 20$m/s, n=660Hz
$n^{'} = \frac{340}{340 - 20 	imes \frac{1}{2}} 	imes 660$
$= \frac{340}{330} 	imes 660 = 680\ Hz$

Q. A car is moving along x-axis with a velocity v=20 m/s. it sounds a whistle of frequency 660 Hz. If the speed of sound is 340 m/s, the apparent frequency heard by the observer O (shown in the figure) is

Explanation

Reviewed by Dr. Abubacker

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