An engine standing at  the platform blows a whistle of frequency 305 Hz. If the velocity of
Channel: Doubtnut
Date: 2020-06-14

An engine standing at  the platform blows a whistle of frequency 305 Hz. If the velocity of sound be 1220 km/h, the frequency of the whistle as heard by a man running towards the engine with a speed of 20 km/s is