When you go over the crest of a hill in a roller coaster, a force appears to lift you up out of your seat. This is a fictitious force.

Question

Quizplus · Accepted Answer

This sensation is due to a reduction in the normal force exerted on you by the seat as the roller coaster goes over the crest, creating a feeling of weightlessness or being lifted out of the seat, which is often described in terms of fictitious forces in a non-inertial reference frame.

When You Go Over the Crest of a Hill in a Roller