1. The problem statement, all variables and given/known data A negative charge is contained by the cube in Figure Ex27.6 ( http://i137.photobucket.com/albums/q208/infinitbelt/p27-06.gif [Broken] ), in which E1 = 13 N/C and E2 = 22 N/C. The electric field is constant over each face of the cube. 2. The attempt at a solution Does the missing electric field vector on the front face point in or out? -I got this as it points in. What is the minimum possible field strength? I thought that it should be 8 NC as that would give -1 NC in the cube. What am I doing wrong?