A roller coaster car of mass 1216 kg slides on a frictionless track starting at a distance 32 m above the bottom of a loop 25 m in diameter. The acceleration of gravity is 9.81 m/s^2 If friction is negligible, what is the magni- tude of the force of the track on the car when the car is at the top of the loop? Answer in units of N. Fn=(mv^2) /R - Fg mgh = .5mv^2 v^2= 2gh = 2*9.81*32 = 627.84 Fn = (1216*627.84)/12.5m - (1216*9.81) = 49147.3152N ??? apparently this is wrong. What did i do wrong?