The Anatomy of a Roller Coaster
To adequately understand the relationship between physics and roller coasters, it is essential to first describe and explain the basic structure of roller coasters. In simple terms, a roller coaster is much like that of a passenger train. To explain, a roller coaster consists of a series of connected cars that move on tracks. However, unlike a train, a roller coaster has no engine, or rather a power source of its own.
There are two major types of roller coasters, characterized mainly by their track structure. The tracks of wooden roller coasters are similar to those of traditional railroad tracks, as metal wheels of the roller coaster roll on a flat metal strip that is bolted to a sturdy running track made of laminated wood (How Roller Coasters Work). A majority of wooden roller coasters have the same wheel design as that of a train, where the inner part of the wheel has a wide lip that prevents the car from rolling off the side of the track. Additionally, wooden roller coasters also have another set of wheels that run underneath the track, keeping the cars from flying up into the air. Wooden coaster tracks are braced by wooden crossties and diagonal support beams; the entire track structure rests on an intricate lattice of wooden or steel beams (How Roller Coasters Work). With the wooden roller coaster structure, designers can combine hills, twists, and turns into an infinite variety of course layouts. In wooden roller coasters, however, the exhilarating motion is mainly up and down.
The second type of major roller coaster, based on tubular steel tracks, was introduced in the 1950s. Consisting of a pair of long steel tubes, this particular track structure is supported by a sturdy, lightweight superstructure made out of slightly larger steel tubes or beams (How Roller Coasters Work). In tubular steel coasters there are wheels that sit on top of the steel track, as well as wheels attached to each car which run along the bottom of the tube and along the sides. This design keeps the car securely anchored to the track, which is critical when the cars run through the structure’s twists, turns, loops, and corkscrews.
How Roller Coasters Work
For the primary duration of a roller coaster ride, a roller coaster is moved only by the forces of inertia and gravity. The only exertion of energy, or rather “work”, occurs at the very beginning of the ride, when the coaster train is pulled up the first hill, which is called the lift hill (Funderstanding Roller Coasters). The purpose of this initial ascent is to build up a reservoir of potential energy. Potential energy, often called energy of position, can be easily explained in relation to a roller coaster ride. Moreover, as the coaster climbs, there is a greater distance of gravity that can pull it down. As the coaster is released at the top of the first hill, gravity takes control, applying a constant downward force on the cars. The tracks of the roller...