1. The problem statement, all variables and given/known data a small solid sphere of mass m and radius r starts from rest and rolls down a hill without slipping. the sphere encounters a loop of radius R where R >> r. Given R determine the min height h such that the ball remains on the track throughout the loop 2. Relevant equations I = 2/5 mR^2 ω = v/r 3. The attempt at a solution highest point requiring most energy is at top of loop: mgh = mg2R + 1/2 Iω^2 mgh = mg2R + 1/2 * 2/5 m r^2 *v^2/r^2 gh = 2Rg + 1/5*v^2 at top of loop, normal force is 0, Fy = N + mg ma = mg m*v^2/R = mg v^2 = gR ... gh = 2Rg + 1/5 Rg h = 11/5 R this is correct?