Roller Coaster Physics

If there are no forces on an object; if it's at rest it will stay at rest and if it's in motion it will continue in motion. If it goes at the same speed and in the same direction it will not seem as exciting. 

Cars go faster than most roller coasters, but cars usually go in a straight line which makes it less exciting.Turns and hills make the roller coaster feel like you are going faster. 

Different forces make the roller coasters go. Motor pulls chains which pull the car up the first hill.

Gravity pulls it down. The first hill is usually the biggest. There can't be a lot of friction or it slows the car down. Smaller hills keep the ride going.

 At the end it slows down and there are brakes to help stop it.

Most roller coasters have different places during the ride that keeps its speed under control.

At the end of the ride, after friction has slowed it down, there are tighter turns and smaller hills so it will seem exciting (tighter turns make the riders feel more force).