Identical charges are fixed at three corners of a square of side
PHYSICS · Subjective · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential
Problem
Identical charges +q are fixed at three corners of a square of side a, and a charge −q is fixed at the fourth corner. A charge +Q is placed at the center of the square. Derive an expression for the magnitude of the net electrostatic force acting on the central charge in terms of k, q, Q, and a.