PURPOSE: To show the doppler effect.
DESCRIPTION: A speaker has long wires as shown in the photo. Turn on the function generator to create a constant tone. Move the speaker towards the students quickly. They will hear the frequency of the tone increase. Move the speaker away from the students quickly. They will hear the frequency of the tone decrease.
This version of the doppler demo is often preferred over the buzzer on a rope, version 3b40.10 because the frequency of the tone can be adjusted. The buzzer on the rope has a very painful tone that cannot be adjusted.
EQUIPMENT: Speaker and function generator, as photographed.
Updated by Jun Qi in 3/24/2000