When a train is approaching the observer, the frequency of the whistle is 100 cps. When it has passed observer, it is 50 cps. Calculate the frequncy when the observer moves with the train.

When a train approaches a stationary observer, the apparent frequency of the whistle is n' and when the same train recedes away from the observer, the apparent frequency is n" . Then the apperent frquency n when the observer sitting in the train is :

An observer on a railway platform noticed that when a train passed through the station, at a speed of 72 kg h^(-1) , the frequency of the whistle appeared to drop by 500 Hz. Calculate the actual frequency of the note produced by the whistle. Velocity of sound in air = 340 ms^(-1) .

Statement I: A person is standing near a railway trach. A train is moving on the track. As the train is approaching the person, apparent freqeuncy keeps on increasing and when the train has passed the person, then apparent freqeuncy keeps on decreasing. Statement II: When train is approaching the person then, f=f_0[(c )/(c-u)] and when train is moving away from person f=f_0[(c )/(c+u)] Here, c is velocity of sound u is velocity of train and f_0 is original frequency of whistle.

A train blowing its whistle moves with a constant velocity v away from an observer on the ground. The ratio of the natural frequency of the whistle to that measured by the observer is found to be 1.2 . If the train is not rest and the observer moves away from it at the same velocity, this ratio would be given by

A train moves towards a stationary observer with a speed of 40 m/s. The observer records the frequency of the train's whistle as f_(1) . But when the train's speed is reduced to 20 m/s, the frequency of the whistle recored by him is f_(2) . What is the ratio (f_(1))/(f_(2)) , if the speed of sound in air is 340 m/s ?

Two trains one moving at a speed of 30 mile/h and iother at 60 mile/h, approaching each other. When a faster train blows a whistle, the apparent friequency of the note head by an observer at rest behind the faster train is 1852 Hz. Calculate the frequency of note produced by faster train (Assume speed of sound to be 1100 ft/s)

The speed of sound in air at a given temperature is 350 m/ s. An engine blows whistle at a frequency of 1200 cps. It is approaching the observer with velocity 50 m/s. The apparent frequency in cps heard by the observer will be

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 )

An observer and source are approaching one another with a relative velocity of 50 m/s. If the true frequency of the source is 1000 Hz, determine the observed frequency when (i) Observer is stationary (ii) Source is stationary