Newton’s first law is the Law of Inertia. This states that an object at rest stays at rest, or an object in motion stays in motion until unbalanced forces act upon it. Since an object at rest stays at rest, all roller coasters have to be pushed or pulled to get started. As the cars go uphill, they store potential energy. Roller coaster cars will gain enough energy from the lift hill to be powered through the rest of the ride. Once put into motion, they will not stop until the brakes are applied at the end of the ride.