15. A ball is dropped on a slope like the one shown in Figure 2.116a. A. If we assume that the surface is frictionless, what will be the velocity at point P? (Ignores the effects of rolling and rotating the ball) b. The same ball is dropped on a slope (without friction) as shown in Figure 2.116b. What is the velocity at point Q? c. Explain why the ball reaches point P faster than point Q. d. But if the balls roll down the slopes. Suggest how this fact affects your responses.