The Physics of Roller Coasters: How Do They Work?

From the moment the cars of a roller coaster break away from the start of the ride to when we return back to the station, there is a lot of physical science behind the thrilling experience. The physics of roller coasters involves a wide range of concepts, from basic mechanics to energy and forces, to keep riders safe and to maximize the excitement and adventure of the ride. Let’s take a look at the science behind one of the most popular attractions in the world.

History of Roller Coasters

The first roller coasters appeared during the 19th century in France. They typically consisted of a steep slope, with gravity as the only force that propelled the cars down the track. The ride would end at a flat area. As the popularity of roller coasters grew, more complex designs started to appear. The first steel roller coaster was LaMarcus Adna Thompson’s “Switchback Railway” at Coney Island, New York, in the 1880s. Today, the world of the roller coaster has transformed into extreme engineering feats, complete with banked turns, loops, incredible speeds, and other mind-boggling features.

Energy Used in Roller Coasters

When we look at the physics of roller coasters, we must consider the two main types of energy they utilize: gravitational energy and kinetic energy.

Gravitational Energy: Once cars leave the station and ascend the first hill, they are powered by their own gravitational energy – this is the force of gravity that pulls the cars down the track.

Kinetic Energy: When cars start to lose speed at the top of the hill, the kinetic energy of the coaster is converted into another form of energy, usually heat. This is done with the use of brakes.

Laws of Motion in Roller Coasters

The physics of roller coasters is based on three fundamental laws of motion, defined by Isaac Newton.

Law of Inertia: When you’re riding a roller coaster, the inertia of the car contributes to why you experience the feeling of weightlessness in certain parts of the ride. Basically, the law of inertia states that an object will remain at rest or in motion until it is acted upon by a external force.

Law of Acceleration: Acceleration, which is a change in speed, is caused by forces acting upon an object, such as gravity. Roller coasters constantly speed up and slow down as they travel around the track, and, depending on the design, they may experience prolonged periods of speed and weightlessness when they go around a track loop or after a steep hill.

Law of Force and Action: This law explains why one can feel the sensation of the g-force on a roller coaster. Basically, the force of the ride’s acceleration is equal to the opposite reaction of the seat pushing back against a rider.

Forces Acting on Riders

In addition to the acceleration caused by speed, there are several other forces acting upon riders.

Centripetal Force: This type of force is created by a curved path and is directed toward the center of rotational motion, such as when a roller coaster goes around a bend or through a loop. It is best experienced during the sharp turns of a roller coaster, when one feels pushed against the side of the car.

G-Force: G-force (or the gravitational force) is caused by acceleration and deceleration due to gravity and gives one the sensation of weightlessness, or pseudo-gravity. It can create a feeling of being pressed down into one’s seat or pushed out into the air depending on the direction of the turn and the speed of the ride.

Lift Hill and Derailing

The most important part of the roller coaster is the lift hill – or the area where the cars are propelled up a steep slope. The lift hill is generally situated at the beginning of the ride, and its purpose is to provide the cars with the necessary potential energy. This potential energy is then converted into kinetic energy as the cars go down the hill.

Raising the height of the lift hill also increases the horsepower necessary to force cars up the hill, since they must overcome the additional gravitational force. To prevent derailing, the weight of the cars must not exceed the speed of the lift hill so that they don’t build up too much speed before the track flattens out.

A ride on a roller coaster is an adrenaline-filled experience. Thanks to the physics of roller coasters, every movement, twist and turn is made possible by the laws of motion, energy, acceleration and gravity. By understanding the forces and motions that work in harmony to keep riders safe and make the ride enjoyable, we can experience the thrilling adventure that a roller coaster offers.