Physics307L:People/Long/Lightspeed: Difference between revisions
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::<math>2.9979\times 10^{8} m/s</math> | ::<math>2.9979\times 10^{8} m/s</math> | ||
The uncertainty in our voltage measurements is the | The uncertainty in our voltage measurements is the variation of the signal on the oscilloscope from our reported value. It is '''not''' the standard 68% confidence uncertainty. | ||
Revision as of 15:25, 27 September 2009
Speed of Light Lab Summary
In the speed of light experiment, my partner Tom and I calculated a value for the speed of light using an LED circuit and a Photomultiplier tube (PMT). Our procedure for this lab was based on instructions provided by Professor Gold’s manual. My lab notebook including raw data, and our setup can be found here.
Data Summary
The following data was obtained by measuring the time delay between the LED emitting a pulse, and the PMT receiving the signal. The delay is then converted to a voltage by a time amplitude converter, which we then measured through an oscilloscope. We repeated this procedure with varying distances, a total of six trials. See my lab notebook for more details on setup, and raw data.
- Our measured mean speed of light based on the six trials:
- [math]\displaystyle{ 2.9461 \pm 0.0437\times 10^{8} m/s }[/math]
- The accepted value of the speed of light is:
- [math]\displaystyle{ 2.9979\times 10^{8} m/s }[/math]
The uncertainty in our voltage measurements is the variation of the signal on the oscilloscope from our reported value. It is not the standard 68% confidence uncertainty.
