Two identical charged spheres suspended from a common point by two massless strings of lengths l, are initially at a distance d (d < < l) apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity v. Then v varies as a function of the distance x between the spheres, as
(a) v ∝ x -1/2
(b) v ∝ x-1
(c) v ∝ x1/2
(d) v ∝ x
