Physics - Sound Wave Question with Solution | TestHub

Given : $v_0=\frac{v}{5}\Rightarrow v_0=\frac{320}{5}=64\mathrm{m}/\mathrm{s}$ When observer moves towards the stationary source, then $$n^{\prime }=\left(\frac{v+v_o}{v}\right)n$$ $$\begin{array}{l}{n}^{\prime }=\left(\frac{320+64}{320}\right)n\\ n^{\prime }=\left(\frac{384}{320}\right)n\\ \frac{n^{\prime }}{n}=\frac{384}{320}\end{array}$$ Hence, percentage increase $$\begin{array}{rl}\left(\frac{n^{\prime }-n}{n}\right)& =\left(\frac{384-320}{320}\times 100\right)\%\\ & =\left(\frac{64}{320}\times 100\right)\%=20\%\end{array}$$