engine as heard by an observer, when the engine moves towards the observer with aspeed , is n. If the engine is stationary and the observer moves towards the engine with the same speed v,, the apparent frequency of the same whistle will be :

Consider the droppler effect in two cases. In the first case an observer moves towards a stationary sound-source, with a speed V_(1) . In the second case, the observer is at rest, and the source moves towards the observer with the same speed V_(1) . Then the frequency heard by the observer

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is

An observer moves towards a stationary source of sound. The percentage change in the apparent frequency is

When the source is moving towards the stationary observer, the apparent frequency is given by

If a source emitting waves of frequency f moves towards an observer with a velocity (v)/(4) and the observer moves away from the source with a velocity (v)/(6) , the apparent frequency as heard by the observer will be (v=velocity of sound)

When an observer moves towards a stationary source, then the apparent pitch will

A source is approaching towards an observer with constant speed along the line joining them. After crossing the observer, source recedes from observer with same speed. Let f is apparent frequency heard by observer. Then,