Physics - Sound Wave Question with Solution | TestHub

1st the car is the source and at the cliff, one observes$f^{\text{'}}$.

$\therefore f^{\text{'}}=\frac{v}{v-v_{\text{s}}}f$

2^ndcliff is now source. It emits frequency$f^{\text{'}}$and the observer is now the driver who observes$f^{\text{'}\text{'}}$.

$\therefore f^{\text{'}\text{'}}=\left[\frac{v+v_0}{v}\right]f^{\text{'}}$or$2f=\left[\frac{v+v_0}{v-v_{\text{s}}}\right]f$

$\Rightarrow 2v-2v_0=v+v_0\Rightarrow v=v_0+2v_0$$\left[\text{as }{\mathit{\text{v}}}_{\text{s}}=v_0\right]$

$\Rightarrow v_0=\frac{v}{3}$