A marble rolls down a track and around a loop-the-loop of radius R. The marble has mass m and radius r. What minimum height h must the track have for the marble to make it around the loop-the-loop without falling off?
mgh = 1/2mv^2 + 1/2Iw^2
The Attempt at a Solution
mgh= 1/2mv^2 + 1/2mr^2*v^2/r^2
At the top of the loop
it just need the minimum velocity therefore the normal will be zero
h=3/2*r which is incorrect please help