a) Two identical point charges of q = +1.50 x 10-8 C are separated by a distance of 1.10 m. What is the minimum amount of work required by an external force to move them closer together so that they are only 0.60 m apart?
b) What is the electric potential energy of three equal positive charges of 1.20 µC when they are arranged to form a triangle 2.50 x 10-3 m on a side?