4. Consider the falling and rolling motion of the ball in the following two resistance-free situations. In one situation, the ball falls off the top of the platform to the floor. In the other situation, the ball rolls from the top
of the platform along the staircase-like pathway to the floor. For each situation, indicate what types of forces
are doing work upon the ball. Indicate whether the energy of the ball is conserved and explain why. Finally, fill
in the blanks for the 2-kg ball.