A skateboarder with his board can be modeled as a particle of mass 70.0 kg, loca
ID: 2183139 • Letter: A
Question
A skateboarder with his board can be modeled as a particle of mass 70.0 kg, located at his center of mass (which we will study in a later chapter). As shown in the figure below, the skateboarder starts from rest in a crouching position at one lip of a half-pipe (point ). The half-pipe is one half of a cylinder of radius 6.70 m with its axis horizontal. On his descent, the skateboarder moves without friction so that his center of mass moves through one quarter of a circle of radius 6.20 m.(a) Find his speed at the bottom of the half-pipe (point ).
m/s
(b) Immediately after passing point , he stands up and raises his arms, lifting his center of mass from 0.500 m to 0.880 m above the concrete (point ). Next, the skateboarder glides upward with his center of mass moving in a quarter circle of radius 5.82 m. His body is horizontal when he passes point , the far lip of the half-pipe. As he passes through point , the speed of the skateboarder is 4.73 m/s. How much chemical potential energy in the body of the skateboarder was converted to mechanical energy in the skateboarder-Earth system when he stood up at point ?
J
(c) How high above point does he rise?
Explanation / Answer
figure ???? please post the figure