I'm supposed to calculate the total charge of the disc using the Trapezoidal Rule modified for use with Cartesian coordinates. The equation I'm using for each ring is π(change in R)(charge of inner radius + charge of outer radius). The total charge is supposed to be 7.739 x 10^-15, but I am getting 7.19 x 10^-15. What is wrong with my equation?
Surface charge density data, Os(r), in [C/m], versus radius, r in [m], on the upper patch:
r (m)
pr) [C/m], upper 1.075E-07 1.085E-07
0.00E+00
1.00E-05
2.00E-05
1.105E-07
3.00E-05
1.135E-07
4.00E-05
1.175E-07
5.00E-05
1.235E-07
6.00E-05
1.336E-07
7.00E-05
1.486E-07
8.00E-05
1.767E-07
9.00E-05
2.420E-07
1.00E-04
1.085E-06