A) \[\frac{v}{\sqrt{2}}\]
B) \[\frac{v}{2}\]
C) \[\frac{v}{3}\]
D) \[\frac{v}{4}\]
Correct Answer: C
Solution :
If\[{{v}_{s}}\]be the velocity of car, then frequency of sound striking the cliff \[n'=\frac{v\times n}{v-{{v}_{s}}}\] The frequency of sound heard an reflection \[n''=\frac{(v+{{v}_{s}})n'}{v}=\frac{(v+{{v}_{s}})}{v}\times \frac{v\times n}{(v-{{v}_{s}})}\] \[\frac{n''}{n}=\frac{v+{{v}_{s}}}{v-{{v}_{s}}}=2\] \[v+{{v}_{s}}=2v-2{{v}_{s}}\] Or \[3{{v}_{s}}=v\] Or \[{{v}_{s}}=\frac{v}{3}\]
You need to login to perform this action.
You will be redirected in
3 sec
