One train is approaching an observer at rest and another train is receding from him with the same velocity `4 m//s` . Both trains blow whistles of same frequency of `243 H_(Z)` . The beat frequency in `H_(Z)` as heard by observer is (speed of sound in air = `320 m//s`)

One train is approaching an observer at rest and another train is receding him with same velocity 4 ms^(-1) . Both the trains blow whistles of same frequency of 243 Hz. The beat frequency in Hz as heard by the observer is (speed of sound in air= 320ms^(-1) )

A person is observing two trains, one is approaching him with a velocity of of 4 m/s while the other is receding from him with the same velocity. IF both the trains blow their respective whistles of frequency 240 hertz, the beat frequency heard by the observer will be (speed of sound in air = 320 m/s)

On a platform a man is watching two trains one leaving the station the other approaching the station, both with the same velocity 2 m/s and blowing their horn with a frequency 480 Hz. The number of beats heard by the man will be (Velocity of sound in air is 320 m/s)

A person is listening to two trains one approaching him while the other moving away from him. The speed of both the trains is 5 m/s. If both trains give off whistle of their nature frequency of 280 Hz then the observer will hear ... no of beats/s. (Velocity of sound = 350 m/s)

A train moving with speed 72 Km/hr blows its whistle of 200 Hz.What frequency is heard by a stationary observer?[velocity of sound in air = 330 m(s)^-1 ]

A train in approaching a station with a uniform velocity of 72kmph and the frequency of the whistle of that train is 480Hz . The apparent increase in the frequency of that whistle heard by a stationary observer on the platform is (Velocity of sound in air is 340m//s )