Physics307L F09:People/Rivera/Notebook/070917

Set up TAC with Start and Stop both from emitter to make sure it was working and to check the delay.

got 1.34 volts for 10 ft of cable about 1.34 ns for delay time in cable.

Reconnected Start from emitter, Start to detector

for initial test Readings 1st stick reading 75cm 3.8V => 38ns

2nd stick reading 95cm 3.7V => 37ns

3rd stick reading 55cm 3.9V => 39ns

over 40nm get 2ns difference giving speed of light as .4m/2x10^-9s=2x10^8m/s (+/-1x10^8)

4th Stick reading 55cm PM ->-.8V 2.16V => 21.6ns

5th stick reading 80cm pm ->-.8v 1.98V +/-.02 =>19.8ns

speed of light from 4th to 5th .25m/1.8x10^-9s = 1.4x10^8m/s off by a factor of 2

6th stick reading 105cm 1.84V => 18.4ns

speed of light from 5th to 6th.25m/1.4x10^-9s = 1.8x10^8

Error because of reflection? or other.