First slide

Doppler

Question

A rocket is going towards moon with a speed v. The astronaut in the rocket sends signals of frequency n towards the moon and receives them back on reflection from the moon. What will be the frequency of the signal received by the astronaut ? (Take v < <c)

Moderate

A

$\frac{cn}{c â v}$
B

$\frac{cn}{c â 2 v}$
C

$\frac{2 Vn}{c}$
D

$\frac{2 c n}{V}$

Solution

In this case, we can assume that both the source and observer are moving towards each other with velocity v' If c be the velocity of signal, then
${Î·}^{â²} = (\frac{c + v}{c â v}) n or n^{â²} = [\frac{(C + V) (C â V)}{(C â V)^{2}}] n n = [\frac{c^{2} â v^{2}}{c^{2} + v^{2} â 2 cv}] n = (\frac{c^{2}}{c^{2} â 2 cv}) n (âµ c >> v) (\frac{c}{c â 2 v}) n$

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