Two uncharged spherical conductors of identical mass and shape are suspended from a ceiling by insulating strings. The conductors are then given charges q_a = Q and q_b = 3Q.

The two conductors are now brought together and made to touch, then released. How do the new angles compare with the old angles?

A) New angles are larger than the old angles

B) New angles are smaller than the old angles

C) New angles are equal to the old angles

D) More information is needed

Solution: A. The larger the electrostatic force, the larger the angles. When the conductors are brought together, the charge will distribute evenly, giving each conductor a charge of 2Q. The electrostatic force is proportional to the product of the charges. 2Q*2Q > 3Q*Q, so the forces and angles are larger.