Rolling friction: occurs between a rolling object and the surface it is rolling in. The rolling object is The the wheels and it is rolling on the track

Fluid Friction: is the friction between a solid object as it moves through a liquid or a gas. Fluid friction is the air passing pass the people and the roller coaster

Sliding friction: is friction caused by moving two flat surfaces against each other. Sliding friction is the people moving in the roller coaster

Friction Types

Static friction: is the frictional force that opposes any attempt to move a stationary object along a surface. There would be static friction between the wheels and track when it stops.