Hi, I don't want help solving this problem, just a method to complete it without using calculus. Here it is: A thin glass rod is bent into a semicircle of radius r. A charge +q is uniformly distributed along the upper half, and a charge -q is uniformly distributed along the lower half. Find the magnitude and direction of the electric field E at the center of the semicircle. (which is the center of a normal circle if one existed in this problem) The key for me is, how to solve without using calculus, if that is possible. Thanks.