A uniform spherical ball of radius rolls without slipping along a nearly frictionless loop-the-loop track of radius 1.0 m (see figure). It starts at a height h above the bottom of the loop. If the ball is not to leave the track at the top of the loop, what is the smallest value h can have (in meters)? (Hint: when the ball is just about to lose contact with the track, the normal force N = 0. Also, don't forget about the centripetal acceleration.)