At the beginning of the ride on points A and B it is balanced because the rIde is stopped and not moving. At the end of the ride point N is balanced because it stops moving. During the ride points C,D,E,G,H,I,J,L, and M are unbalanced because they are moving around during the ride and going down hill. A roller coaster has to go down hills which is an unbalanced force and goes down the hill because of gravity. When a roller coaster goes up hills it is also an unbalanced force because it is going up and gravity pulls objects down instead of letting objects go up. The only time where forces are balanced on a roller coaster is when the ride is just starting or when the ride is ending.