Problem 3.3

Two small equally charged spheres, each of mass \(m,\) are suspended from the same point by silk threads of length l. The distance between the spheres \(x \ll l\). Find the rate \(d q / d t\) with which the charge leaks off each sphere if their approach velocity varies as \(v=a / \sqrt{x},\) where \(a\) is a constant.