Spark image

Doppler effect

The diagram shows the Doppler effect. Sound waves are being emitted by the plane - a moving source. The waves are 'squashed' in the front of the plane and spread out behind the plane. The speed of the plane is less than the speed of the waves and it can be changed by using the slider. The faster the plane flies the more the waves in front of the plane are squashed.
Always press Reset before moving the slider.

© Keith Gibbs/John Bourne 2012