Question

Four point charges are at the corners of a square of side a as shown in the figure below. Determine the magnitude and direction of the resultant electric force onq, with ke, q, and a left in symbolic form. (Let B = 1.5q and C = 4q. Let the +x-axis be pointing to the right.)

Answer 1

F = F1 (1,0) + F2 (1/?2, 1/?2) + F3 (0,1)

F = kq(1.5q)/a² (1,0) + kq(8q)/(a?2)² (1/?2, 1/?2) + kq(1.5q)/a² (0,1)

F = ((2?2 k q²)/a² + (1.5 k q²)/a², (2?2 k q²)/a² + (1.5 k q²)/a²)

|F| = ?2 |(2 ?2 k q²)/a² + (1.5 k q²)/a²|