A) 200 Hz
B) 244 Hz
C) 150 Hz
D) 80 Hz
Correct Answer: B
Solution :
From Doppler's effect, perceived frequency is \[n'=n\left( \frac{v-{{v}_{0}}}{v-{{v}_{s}}} \right)\] \[{{v}_{s}}=72\,km/h=\frac{72\times 1000}{60\times 60}=20\,m/s\] \[{{v}_{0}}=0,\,v=332m/s,\,n'=260\,Hz\] \[260=n\left( \frac{332}{332-20} \right)\] \[\Rightarrow \] \[n=\frac{260-312}{332}=244\,Hz\]You need to login to perform this action.
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