What is the reason for listening a higher frequency when a source of sound moves towards a stationary listener?

A source of sound moves towards an observer

A source of sound moves towards an observe.

(a) What is Dappler effect? The frequency r of a source of sound appears to be n' to a stationary listener when the source is moving with velocity V_s away from him. The velocity of sound is V. Write an expression for n' in terms of r, V and V_s . (b) Distinguish between the characteristics of progressive and stationary waves. Use diagrams to distinguish.

The wave length of the sound produced by a source is 0.8m. If the source moves towards the stationary listener at 32 ms^(-1) what is the apparent wave length of sound if the velocity of sound is 320 ms^(-1)

What physical change occurs when source of sound waves is at rest and the listener moves?

To a stationary man the frequency of a sound source moving towards the man appears to be

A railroad train is travelling at 30 m/s in still air. The frequency of the note emitted by locomotive whistle is 500 Hz. What is the frequency of the sound waves heard by a stationary listener (a) in front of the train and (b) behind the train? (speed of sound is 345m/s.)

A railroad train is travelling at 30(m)/(s) in still air. The frequency of the note emitted by locomotive whistle is 500 Hz. Speed of sound is 345(m)/(s) . Q. What is the frequency of the sound waves heard by a stationary listener in front of the train?

When the medium moves and the source and observer are stationary:

A source of sound emitting a note of constant frequency is moving towards a stationary listener and then recedes from the listener with constant velocity maintained throughout the motion. The frequency heard by the listener (f). when plotted against time (t) will give the following curve(s).