Cavendish Experiment: Results (Home Experiment Main Apparatus Results Conclusions )
As described in apparatus we eventualy end up with a graph showing the change in voltage (position) over time (titled Counts). We run one series with the masses out of the way (Center) and then another series with the Large and small masses next to each other, either Left or Right depending on which small mass has a large mass is in front of it. This gives us two or more graphs like these:


From each series we can calculate the periods (T) to get an average period. We also find the average center point of each series and then compare the Center series (as the zro point) to the other series, either Left or Right; this gives us our Delta X. We can use this to find the difference angle ,theta, by tan (theta) = Delta X / 2 A Where A is the distance to the sensor. We then tabulate the data as:

3.06.2002	I	II	Average
Delta X (Left)	1.6587 cm	1.1298 cm	-
Theta	0.022722 Rad	0.015477 Rad	0.019099 Rad
Period (T)	652.4 s	670.1 s	661.3 s

3.13.2002	Left	Center	Right	Average
center point	3.1851 cm	1.8838 cm	0.82752 cm	-
Delta X	1.3013 cm	-	1.0563 cm	-
Theta	0.01783 Rad	-	0.01447 Rad	-
Period (T)	654 s	670 s	647 s	657 s

Based on the data in these tables and the measured values of the apparatus components, I was able to calculate the following values of G:

Measured G	-	-
3.06.2002 Left	5.6916 E-11	-
3.13.2002 Left	5.3811 E-11	-
3.13.2002 Right	4.3679 E-11	-
Average Measured G	5.1469 E-11	+/- 6.9224 E-12
Average Sigma	3.9966 E-12	-
Known G	6.6726 E-11	-
Number of Sigma from Known	3.82	-

Updated 5/10/2002