Oscillations and Waves > Waves > Doppler Effect DCS# 3B40.25

DOPPLER REED



APPARATUS
doppler reed apparatus
202-07-E
variable speed motor
101-11-D

DESCRIPTION
The motor-driven apparatus has a reed on one end and a counterweight on the other.  Rotate the apparatus counterclockwise at the lowest speed necessary for the reed to sound (about 100-150 rpms).  The pitch is higher when the reed is approaching and lower when it is receding.