Two engines pass each other moving in opposite directions with uniform speed of 30 m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330 m/sec :

Question

Two engines pass each other moving in opposite directions with uniform speed of 30 m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330 m/sec : (A) 450 Hz (B) 540 Hz (C) 648 Hz (D) 270 Hz

Tardigrade Admin · Accepted Answer

f ' =(v-v0/v-vs) f =(330+30/330-30)×540 =(360/300)×540 =648Hz

Q. Two engines pass each other moving in opposite directions with uniform speed of $30 m / s$ . One of them is blowing a whistle of frequency $540 Hz$ . Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is $330 m / sec$ :

450 Hz

540 Hz

648 Hz

270 Hz

$f^{'} = \frac{v - v _{0}}{v - v _{s}} f$
$= \frac{330 + 30}{330 - 30} \times 540$
$= \frac{360}{300} \times 540$
$= 648 Hz$

Q. Two engines pass each other moving in opposite directions with uniform speed of 30m/s. One of them is blowing a whistle of frequency 540Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330m/sec :