An advantage of parallel circuits is that a. it is the simplest type of circuit to make. b. electrons can only take one path, so the flow of energy is always known. c. if one part of the circuit is not working, the other parts can still work. d. when one part of the circuit breaks, the whole circuit must be replaced.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.