In the roller coaster loop-the-loop shown, the frictionless car starts with zero velocity at a height h. The normal force at the top of the loop (point A) is found to be three times the weight of the cart. Take the radius of the loop as R.

(a) find out h in terms of R and g.

(b) find out the normal force on the car at point B
where 2 = 30° from the horizontal. Express this as a number or fraction times the weight of the car.