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An engine moving away from a vertical cl...

An engine moving away from a vertical cliff blows a born at a frequency f. Its speed is 0.5% of the speed of sound in air. The frequency of the reflected sound received at the engine is

A

0.990f

B

0.995f

C

1.005f

D

1.010f

Text Solution

Verified by Experts

The correct Answer is:
A
`f_(1)=f[(v)/(v+v_(s))]`
`implies f_(R)=f_(1)[(v-v_(s))/(v)]=f_(0)[(v-v_(s))/(v+v_(s))]`
`implies f_(R)=f[(1-v_(s)//v)/(1+v_(s)//v)]=f[(1-0.005)/(1+0.005)]=0.990f`.
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