7. Use the diagram and the table to label the energy conversion of this roller coaster based on the position. Identify the lowest value, highest values, when at about 1/2 , 3/4 or 1/4 of the original value or maximum value.

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.