Physics307L:People/Frye/SppedOfLight

Speed of Light
This lab was performed in the senior laboratory in the UNM physics building on September 27th and October 4th with Alex Benedict

Summary and Results
For this experiment we followed the procedure of lab number 10 in Dr. Gold's lab manual.

We used a PMT, LED, and TAC to measure the time it took for a pulse of light to travel a distance. We started with the LED at some distance from the PMT. We then measured the voltage from the TAC, recorded it in our google docs spreadsheet then moved the LED closer and repeated.

On September 27, we moved the LED by 25cm each measurement and did 6 trials. We were still getting familiar with the technique on the first day so we did more runs the next week and changed the distance by less each measurement. On October 4, we moved the LED 10cm closer each time and did this 10 times to cover 1.0m each trial. We did 10 trials. We then did a linear fit of each trial to obtain the slope of the line. The we averaged the slopes from all 10 trials to obtain our final result. Our measured speed of light is 32.685 cm/ns +/- (2.448 cm/ns). The accepted value of the speed of light is 29.979 cm/ns

Links
[Dr. Gold's Lab Manual]

My Lab Summary

Alex Benedict's Lab Summary

Alex Benedict's Lab Notebook