Question

Question #1231a

Answer 1

Newton's first law is about inertia. Inertia is a the property of matter to resist change, i.e. moving things keep moving and static things remain static.

Roller coasters rely on inertia by affecting the coasting car via the roller track. The track has peaks and valleys; that are coated to minimize friction. The car's mass rolls down the valleys and continues moving forward until there is change in the track. When a peak is met, the car's inertia enables it to coast up, but it is decelerated by the force of gravity. If you notice, each subsequent peak is smaller than its predecessor. This is because you can never have more energy than that initial peak.

Basically the coaster's peaks, valleys, and loop-de-loops are using the car's inertia to create the motion of the "falling" coaster.

Here is a decription of the kinetic and potential energy explaination of roller coasters: here

Here is a simulation, where you can play and experiment with inertia and energy: here