Doppler Shift Data Record

Doppler Shift

Experiment 1

We use a Mickelson interferometer to measure the doppler effect. The reflector of one arm of the interferometer is place on the back of a toy train and allowed to move. The interference pattern is measured with a photo-detector and analyzed using a oscilloscope and a spectrum analyzer.

Here, the beat frequency is measured, which is used to find the Doppler shift in the beam incident on the train. The Doppler shift can then be used to find the ratio of the speed of the train to the speed of light.

In this experiment we measure the beat frequency with the spectrum analyzer, and the time of the train to travel its track (a known distance).

Data Length: .795 m

Times:

3.87s, 3.92s, 3.77s, 3.87s

Velocity: ~.21 m/s file 22-27

Experiment 2, slow wheel We need the radius of the wheel, the period of the spinning wheel, and beat frequency.

Average period .414s

Diameter: .1m

Speed of circumference: .759m/s

file 28-37