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 separation between the suspension points being 5 cm. In equilibrium, the sepaation between the balls is 3 cm. Find the mass of each ball and the tension in the stirngs. The charge on each ball ahs a magnitude 2.0×10−8 C.
From equation (i) and (ii)