Three point charges, A = 2.2 µC, B = 7.5 µC, and C = -3.9 µC, are located at the corners of an equilateral triangle . Find the magnitude and direction of the electric field at the position of the 2.2 µC charge.

magnitude = .
N/C
direction =

1 answer

You need to specify the length of the sides of the triangle, R.

Then compute the two vector forces acting on the 2.2 uC charge. The 7.5 uC charge contributes a repulsive force

F1 = k*2.2*7.5*10^-12/R^2 Newtons

where k is the Coulomb constant and R is the side length in meters.

The other charge (-3.9 uC) will contribute an attractive force, given by the same formula,
F2 = k*3.9*2.2*10^-12/R^2 Newtons,
directed at 120 degrees to F1. Add them as vectors.