Physics - Sound Wave Question with Solution | TestHub

Let the actual frequency of the source be $n$ and the apparent frequency heard by the observer be $n^{\prime }$.

Given that $n^{\prime }=3n$.

Since the apparent frequency is greater than the actual frequency, the observer must be moving towards the stationary source.

The formula for apparent frequency when the observer moves towards a stationary source is:

$n^{\prime }=n\left(\frac{v+v_o}{v}\right)$

Substituting the given values:

$3n=n\left(\frac{v+v_o}{v}\right)$

$3=\frac{v+v_o}{v}$

$3v=v+v_o$

$v_o=2v$

The observer should move with twice the velocity of sound towards the source.

Answer: Twice the velocity of sound towards the source.