Physics - Current Electricity Question with Solution | TestHub

A stationary source emits sound of frequency $f_0=492\mathrm{Hz}$. The sound is reflected by a large car approaching the source with a speed of $2{\mathrm{ms}}^{-1}$. The reflected signal is received by the source and superposed with the original. What will be the beat frequency of the resulting signal in Hz ? (Given that the speed of sound in air is $330{\mathrm{ms}}^{-1}$ and the car reflects the sound at the frequency it has received).