1. The problem statement, all variables and given/known data A thin, square, conducting plate 50.0 cm on a side lies in the xy plane. A total charge of 4.00 x 10-8 C is placed on the plate. Find (a) the charge density on each face of the plate, (b) the electric field just above the plate, and (c) the electric field just below the plate. You may assume the charge density is uniform. 2. Relevant equations σ = Q/A 3. The attempt at a solution a) σ = 4×10^-8 / (.5)^2 / 2 = 8x10^-8 C/m^2 b) Ok using gauss law E = σ / ε = 9.04 kN/C c) my problem is why for part C, the answer is -9.04 kN/C. If my Gaussian surface is below the plane, its area vector is pointing downward, and my positive bottom surface charges electric field is also pointing down, so they are pointing in the same direction, thus E should be positive??