1. The problem statement, all variables and given/known data There are three charged sheets with various charge densities. The following link shows a diagram, and solutions (not mine; these are some professor's solutions but I don't understand them yet): http://www.phy.syr.edu/courses/PHY212.08spring/HW/WHW-3.pdf [Broken] Draw vectors at each of the points A-D to show the direction and relative magnitude at the point due to a) sheet 1 b) sheet 2 c) sheet 3. 2. Relevant equations E field due to infinite sheet = σ/2ε (where ε = permittivity constant and σ = charge density) Flux = ∫ EdA = E*A = |E||A|cos(θ) Gauss' Law: Flux = q(enclosed)/εo 3. The attempt at a solution I know which direction the vectors go, but I don't know what their magnitudes are. Surfing the internet gave me this (scroll to last page): http://www.phy.syr.edu/courses/PHY212.08spring/HW/WHW-3.pdf [Broken] I know that the magnitudes of each vector of the electric field from each individual sheet from points A-D should be equal, because the electric field from a charged sheet doesn't depend on radius (for example, sheet 1's field could give vectors of magnitude |a| at every point). However, I don't understand why sheet 2 (σ = -1), according to the above solutions, has vectors of twice the magnitude of sheets 1 and 3 (σ= +1). What am I missing?