A student releases a small cart at the top of an incline with height H above the floor. The cart experiences very little friction. The student is attempting to cause the cart to go around a vertical loop of radius R without the cart losing contact with the track at the top. The student suggests that the heigt H should equal 2R so that the release height and maximum height of th eloop are the same. However, the student finds that it requires noticably higher hieght than 2R for the cart to go around the loop. Explain why H must be noticably greater than 2R to complete the loop. (Hint: In order for the cart to go around the loop it must have a nonzero velocity at the top of the loop.) answer