A block of mass m slides down an inclined plane into a loop-the-loop of radius r (Fig.

Question:

A block of mass m slides down an inclined plane into a loop-the-loop of radius r (Fig. 7.33).

(a) Neglecting friction, what is the minimum speed the block must have at the highest point of the loop in order to stay in the loop?
(b) At what vertical height on the inclined plane (in terms of the radius of the loop) must the block be released if it is to have the required minimum speed at the top of the loop?