A skateboarder with his board can be modeled as a particle of mass 75.0 kg, loca

Question

A skateboarder with his board can be modeled as a particle of mass 75.0 kg, located at his center of mass. 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 6.90 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 6.40 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 0.990 m above the concrete (point ). Next, the skateboarder glides upward with his center of mass moving in a quarter circle of radius 5.91 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 5.37 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?
m

Explanation / Answer

PE_at top =KE_at bottom mgh =(1/2)mv^2 solve for v = sqrt(2gh) b) a = v^2/r c)Fc =mv^2/r N =Fc +W = m(v^2/r +g)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.