1. The problem statement, all variables and given/known data A boy is seated on the top of a hemispherical mound of ice. He is given a very small push and starts sliding down the ice. Show that he leaves the ice at a point whose height is 2R/3 if the ice is frictionless. (Hint:The normal force vanishes as he leaves the ice.) 2. Relevant equations Conservation of energy. 3. The attempt at a solution I wrote the normal force as function of theta. I then set the normal force equal to the centripetal force so I could get rid of the unknown velocity, but it didn't work out. I do not see any other way to solve this problem.