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