A positive force on the balance indicates a downward force on the silver sphere while a negative force on the balance indicates an upward force on the silver sphere. With that in mind, do the two spheres have like charges or opposite charges? Give your answer as a CER.

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.