Three point charges are located at the corners of an equilat

Three point charges are located at the corners of an equilateral triangle as in the figure below. Find the magnitude and direction of the net electric force on the 0.60 mu C Charge. (Let A = 0.60 mu C. theta = 6.80 mu C, and C = -4.20 mu C.) magnitude N direction degree counterclockwise from the +x-axis

Solution

F₁ = (9 * 10⁹ * 6.8 * 10^-6 * 0.6 * 10^-6) / 0.50²

= 0.147 N

F₂ = (9 * 10⁹ * 6.8 * 10^-6 * 4.2 * 10^-6) / 0.50²

= 1.03 N

sigma F_x = (F₁ + F₂ ) cos 60 = 0.589 N

sigma F_y = (F₁ - F₂ ) sin 60 = -0.765 N

FR = sqrt [F_x² + F_y²] = 0.965 N

theta = tan^-1 [Fy / Fx] = -52.41 deg