Two identical conducting small spheres are placed with their centers 0.395 m apart. One is given a charge of -12.0 nC and the other a charge of -15.0 nC.
(a) Find the electric force exerted by one sphere on the other.(magnitude)
(b) The spheres are connected by a conducting wire. Find the electric force each exerts on the other after they have come to equilibrium. (magnitude)