of Lab7
Speed light
Instructor:
Pro. Tsai
Jiajie Huo(Jacky)
Member:
Yao Bin Yu
Zeyuan (Seth) Guan
1. introduction.
In this experiment, we are generally focusing on using the mirror
reflection and deflation to measure to speed of light.
2. Procedure.
a. First, we set up the instruments as the professor told us.
b. Start the laser beam, we measured the change of the light
point appeared in the flat wood, and record its location.
c. Then we compared the experimental location with the
calculated one.
4. Data Sheet
Voltage
(V)
12
15
18.5
22
25.5
30
34
38.3
43.3
Freq
(Hz)
32
64
96
128
160
192
224
256
288
50
54
60
66
72.5
81.5
88
97
106
115
32
64
96
128
160
192
224
256
288
320
Calibration of Rotating Mirror
700
y = 0.0002x 3 - 0.0721x + 2 11.501x - 93.384
600
Frequency (Hz )
500
400
300
200
100
0
0
20
40
60
80
100
120
140
Voltage (V)
6. Discussion and conclusion.
We did this experiment as a group and therefore, the major
work we need to do is to know the theory behind the experiment
and get the final difference between the calculated distance and
experimental one. As first, our statistic contradicted the theory and
we tried to find out the reason behind it. Then we found some
reasons. First, the unavoidable light from outside, and it had some
influence on our experiment. Second, the lense that deflate the
light had once drop, it may not brought back to the original place.
Third, the instruments had been moved during the experiments
without noticed.