Through some of the conservation of energy problems we've been working recently with the loop the loop (ball rolls down ramp and around a circular track.) there is one concept that is irritating me. This is not a homework problem but a mash up of the driving concepts from a few different problems. At the top, what makes the ball stay up there. The normal force and gravity both point downward. There is no force keeping it up. Or is it that the combination of tangential velocity caused by centripetal acceleration along with the downward forces acts to make the motion follow the loop. Also, to clarify, the centripetal force in this case would be Fn and Fg right?