Physics - Sound Wave Question with Solution | TestHub

Two men are walking along a horizontal straight line in the same direction. The man in front walks at a speed$1.0 m s^{-1}$and the man behind walks at a speed$2.0 m s^{-1}$. A third man is standing at a height$12 m$above the same horizontal line such that all three men are in a vertical plane. The two walking men are blowing identical whistles which emit a sound of frequency$1430 Hz$. The speed of sound in air is$330 m s^{-1}.$At the instant, when the moving men are$10 m$apart, the stationary man is equidistant from them. The frequency of beats in$Hz$, heard by the stationary man at this instant, is __________.