Abody of mass m and negligible size starts from rest and slides down the surface of a frictionless solid sphere of radius r. prove that the body leaves the sphere when 0 = cos(2/3).

Awater slide of length l has a vertical drop of h. abby's mass is m. an average friction force of magnitude f opposes her motion. she starts down the slide at initial speed vi. use work-energy ideas to develop an expression for her speed at the bottom of the slide. then evaluate your result using unit analysis and limiting case analysis. express your answer in terms of the variables h, m, l, vi, f and appropriate constants. vf v f