Rawly has a mass of 79.0 kg, and he is sledding down a hill that is 29.5 m tall. As he goes down the hill, his gravitational potential energy is converted into kinetic energy. When he has descended 21.0 m down the hill, how much kinetic and gravitational potential energy does he have?

Two masses are connected by a rope that hangs over a pulley as shown below. the pulley is a uniform cylinder of radius 푅=0.381meters and mass 푀=3.1푘푔. initially 푚"is on the ground and 푚#rests 2.5 meters above the ground. if the system is released, use conservation of energy to determine the speed of 푚#just before it strikes the ground. assume the pulley bearing is frictionless.