The Open Door Web Site : IB Physics : Waves : The Doppler Effect (continued)

The Open Door Web Site

Waves

The Doppler Effect (continued)

Both the effects illustrated in the diagrams above result in a change in the apparent frequency of the sound (as measured by the observer).

The Doppler Effect is the apparent change in the frequency of a sound wave due to the relative motion of source and observer.

If the frequency of the emitted sound is f and the frequency measured by the observer is f’ then the Doppler shift, f, is defined as

The magnitude of the Doppler shift depends on

a) the frequency of the emitted sound, f

b) the relative velocity of source and observer.

The relative Doppler shift (defined as f/f) depends only on the relative velocity of source and observer.