First slide

Doppler's effect

Question

Two whistles A and B produces notes of frequencies 660 Hz and 596 Hz respectively. There is a listener at the mid-point of the line joining them. Now the whistle B and the listener start moving with speed 30 m/s away from the whistle A. If speed of sound be 330 m/s, how many beats will be heard by the listener

Moderate

A

2
B

4
C

6
D

8

Solution

For observer note of B will not change due to zero relative motion.
Observed frequency of sound produced by A
= $660 \frac{(330 - 30)}{330} = 600 Hz$
$∴$ No. of beats = 600 – 596 = 4

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App