A) \[\frac{v}{3}\]
B) \[\frac{v}{4}\]
C) \[\frac{v}{2}\]
D) \[\frac{v}{\sqrt{2}}\]
Correct Answer: A
Solution :
According to given condition cliff is stationary source of freq. f? where \[f'=\left( \frac{v}{v-{{v}_{\infty }}} \right)\,f\] Freq. heard by the driver \[f''=\left( \frac{v+{{v}_{car}}}{v} \right)f'=\left( \frac{v+{{v}_{car}}}{v-{{v}_{car}}} \right)\,f=2f\] \[\Rightarrow \] s\[v+{{v}_{car}}=2v-2{{v}_{car}}\] \[\Rightarrow \]\[3{{v}_{car}}=v\] \[\Rightarrow \]\[{{v}_{car}}=v/3\]You need to login to perform this action.
You will be redirected in
3 sec