A rocket is moving at a speed of 200 m `s^(-1)` towards a stationary target. While moving, it emits a wave of frequency 1000 Hz. Some of the sound reaching the target gets reflected back to the rocket as an echo. Calculate (1) the frequency of the sound as detected by the target and (2) the frequency of the echo as detected by the rocket.

Explanation

The target is the source (as it is the source of echo) and the rocket's detector if the observer who intercepts the echo of frequency v'. Hence the frequency of the echo as detected by a detector attached to the rocket is
`v''=(v+v_(0))/(v-v_(s))xxv=(330+200)/(330-0)xx2538.5`
`=(530)/(330)xx2538.5`
`~~4077Hz`.