1. The problem statement, all variables and given/known data A total charge of 21 μC is applied to a thin, 1μm square metal plate 72 cm on a side. Find the electric field strength near the plate's surface, far from the edges. 2. Relevant equations I think E = kq/r^2, but I really don't know. 3. The attempt at a solution I am having a hard time figuring out where to start. I know I must find the electric field strength (i.e magnitude), but where do I begin and what do I do to find it. I just know that E = kq1q1/r^2, but there is no second charge so it must be kq1/r^2 correct? Do I use that or something else?