(a) Find his speed at the bottom of the half-pipe (point B). m/s (b) Immediately after passing point®, he stands up and raises his arms, lifting his center of mass and essentially "pumping" energy into the system. Next, the skateboarder glides upward with his center of mass moving in a quarter circle of radius 5.39 m, reaching point D. As he passes through point, the speed of the skateboarder is 4.91 m/s. How much chemical potential energy in the body of the skateboarder was converted to mechanical energy when he stood up at point ? (c) How high above point does he rise? Im

(a) Find his speed at the bottom of the half-pipe (point B). m/s (b) Immediately after passing point®, he stands up and raises his arms, lifting his center of mass and essentially "pumping" energy into the system. Next, the skateboarder glides upward with his center of mass moving in a quarter circle of radius 5.39 m, reaching point D. As he passes through point, the speed of the skateboarder is 4.91 m/s. How much chemical potential energy in the body of the skateboarder was converted to mechanical energy when he stood up at point ? (c) How high above point does he rise? Im