Three identical point charges of +6 μC each are kept at the vertices of an equilateral triangle of side 0.15 m. A fourth charge of −2 μC is placed at the centroid of the triangle.
a. (a) Calculate the magnitude of the net electrostatic force acting on the −2 μC charge.
b. (b) The −2 μC charge is now removed. Determine the magnitude of the net electrostatic force experienced by one of the corner +6 μC charges due to the other two corner charges.