Please help!!!!!!
A solid ball of mass m = 40.1 g and radius r = 10.7 mm rolls without slipping through a loop of radius R = 46.5 cm, as shown in the figure. From what height h should the ball be launched in order to make it through the loop without falling off the track?

http://www.flickr.com/photos/60996491@N03/5613965793/

Question

Please help!!!!!!
A solid ball of mass m = 40.1 g and radius r = 10.7 mm rolls without slipping through a loop of radius R = 46.5 cm, as shown in the figure. From what height h should the ball be launched in order to make it through the loop without falling off the track?

http://www.flickr.com/photos/60996491@N03/5613965793/

anonymous · Answer

http://www.flickr.com/photos/60996491 @N03/5613965793/in/photostream

anonymous · Answer

attachment

anonymous · Answer

T-mg = 0
(mv^2)/r = mg => v² = gr
             PE = KE => mgh = ½mv²
h = (½v²)/g
h = (½gr)/g = (½r)