HELP!!!physics prove question 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 surface, assumed to be fricitionless. show that he leaves the ice at a point who height is 2R/3 3. The attempt at a solution I don't really know how to do this question. However, I know that the normal force disappears as he leaves the ice.