Question

Two point charges are fixed on the x-axis at the locations shown in the figure below. A charge of +8q is located at x =-a an a charge of -6q is located at x +a. A third charge of +q is located on the y-axis at y +b. tq 1 -6g +8q

Answer 1

F_1 = k (q) (6 q)/r^2 F_2 = k q (8 q)/r^2 r - squareroot a^2 + b^2 cos theta = a/r sin theta = b/r tan theta = b/a k = 1/4 phi E_0 F_x = f_1 cos theta + F_2 cos theta = K 6 q^2/r^2 cos theta + 8 k q^2/r^2 cos theta = 14 k q^2/r^2 cos theta = 14 k q^2 a/r^3 F_y = F_2 sin theta minus F_1 sin theta = 8 k q^2/r^2 sin theta minus 6 k q^2/r^2 sin theta = 2 k q^2 l/r^3 F_net = squareroot F^2_x + F^2_y = squareroot (14 k q^2 a/r^3)^2 + (2 k q^2 l/r^3)^2 F_net = 2 k q^2/r^3 squareroot 49 a^2 + b^2 F_net = q^2 (49 a^2 + b^2)^1/2/2 phi E_0 (a^2 + b^2)^3/2 tan phi = Fy/Fx = 2 k q^2 b/r^3/14 k q^2 a/r^3