A COOL PROBLEM!!( challenge to phy. lovers)
Two identical pith balls are charged by rubbing against each other.They are suspended from a horizontal rod through two strings of length 20 cm each, the seperation betwn suspension points being 5 cm.In equilibrium,the seperation betwn balls is 3 cm.Find mass of each ball. The charge on each ball has magnitude 2.0 x 10^(-8) C.