Loop-the-Loop (a) A block of mass m slides from rest on a frictionless loop-the-loop track...

Loop-the-Loop (a) A block of mass m slides from rest on a frictionless loop-the-loop track, as shown in Figure. What is the minimum release height, h, required for the block to maintain contact with the track at all times? Give your answer in terms of the radius of the loop, r. (b) Explain why the release height obtained in part (a) is independent of the block’s mass.

FIGURE