Physics - Sound Wave Question with Solution | TestHub

${\text{f}}^1=\frac{{\text{f}}_0(\text{V}\pm {\text{V}}_0)}{(\text{V}\mp {\text{V}}_{\text{S}})}=\frac{{\text{f}}_0\left(\text{v}\right)}{\text{V}\mp {\text{V}}_{\text{S}}}$

$\mathrm{W}\mathrm{h}\mathrm{e}\mathrm{n}\mathrm{ }\mathrm{a}\mathrm{p}\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{a}\mathrm{c}\mathrm{h}\mathrm{e}\mathrm{s}:2.2\times {10}^3=\frac{{\mathrm{f}}_0\left(300\right)}{300-V_s}$...(i)

$\mathrm{W}\mathrm{h}\mathrm{e}\mathrm{n}\mathrm{ }\mathrm{r}\mathrm{e}\mathrm{c}\mathrm{e}\mathrm{d}\mathrm{e}\mathrm{s}:1.8\times {10}^3=\frac{{\mathrm{f}}_0\left(300\right)}{300+{\mathrm{V}}_{\mathrm{s}}}$...(ii)

Dividing (i) by (ii)

$\frac{2\text{.}2}{1\text{.}8}=\frac{300+{\text{V}}_{\text{S}}}{300-{\text{V}}_{\text{S}}}\Rightarrow \frac{\text{4}}{0\text{.}4}=\frac{600}{2{\text{V}}_{\text{S}}}$

$\mathrm{\Rightarrow }$$V_S = 30 \mathrm{m} {\mathrm{s}}^{-1}$