4 point charges of 50 [nC] each are located at the four corners of a square lying in the x-y plane and centered on the origin (0, 0, 0) in free space. The diagonals of the square are of length 2 m and lies along the x and y axes. (a) Calculate the total force F on each of the charges by the other three charges, (b) What is the electric potential at the center of the square due to all four charges. (c) What is the electric field intensity at the center of the square due to all four charges.