a. 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 separation between the balls is 3 cm. Find the mass of each ball and the tension in the strings. The charge on each ball has a magnitude 2 0 x 10-8 C. equilibrium is found to be 4 cm. Find the charge on each sphere.
b. Two identical pith balls, each carrying a charge q, are suspended from a common point by two strings of equal length I. Find the mass of each ball if the angle between the strings is 20 in equilibrium.