Two infinite-plane non-conducting, thin sheets of uniform surface charge p1 = 13.35 uC/m2 and p2 = -8.65 uC/m2) are parallel to each other and d = 0.245 m apart. (As shown in the diagram below.) What is the electric field between the sheets? (Note: the field is positive if it is parallel to the vector x).
Epsilon not = 8.85e-12 (SI Units)
The Attempt at a Solution
The distance between the sheets should not matter in calculating the E-field between them because the E-field between them is uniform. We are given two sigmas and since the net charge on the field is toward the negative plane we just sum the two over 2*epsilon_not, and Epsilon not is a constant.
(sigma1 + sigma2)/(2*epsilon_not) = E-field
(13.35e-6 + 8.65e-6)/(2*epsilon_not) = 1.2e6 N/C
Than since the E-field is perpendicular to the planes, but pointing in the opposite direction of positive X the answer becomes negative.
Answer: -1.2e6 N/C (unfortunately I tried this and did not get the problem right)
What did I get wrong?