How Roller Coasters Function By Matthew Olszack and Ivan Introduction • Amusement parks keep coming out with faster and more complex roller coasters every year. However, the fundamental principles that function in a roller coaster remain the same. These principles include basic inertial, gravitational and centripetal forces. These forces are manipulated into the roller coasters to create an exhilarating roller coaster ride. • In this presentation we will go through the various principles that keep roller coasters twisting and turning around the tracks. Energy • At first glance, a roller coaster looks something like a passenger train. It consists of a series of connected cars that move on tracks. What differs a passenger train from a roller coaster is that a roller coaster is moved by forces such as inertia and gravity. A passenger train is moved by an engine or a power source of its own. Energy is also generated in a roller coaster by gravity. Energy exertion occurs when the roller coaster is pulled up the first hill (called the lift hill). The purpose of this initial energy is to build up potential energy. Potential energy occurs as the coaster gets higher in the air creating a greater distance for gravity to pull it down. When the roller coaster descends, this creates kinetic energy. Up and Down the Tracks • According to Newton’s first law of motion, an object in motion tends to stay in motion; The roller coaster will maintain a forward velocity even when it is moving up the track as the kinetic energy exceeds the gravitational pull. When the coaster proceeds up one of the smaller hills, the energy changes from kinetic to potential energy. The roller coasters speed fluctuates throughout the ride because of the constant change from kinetic energy to potential energy. The Pepsi Max Big One, at Black pool Pleasure This makes the roller coaster ride so Beach: much fun. This first hill drops the train 205 ft (62 m) at 74 mph (119 kph). • You might be wondering why in most roller coaster the hills decrease. This is because the energy that is built up in the lift hill is eventually lost to friction between the train and the track. When the train comes to the end of the track it has almost lost all of it’s energy. Wooden Roller Coasters • Wooden roller coasters resemble the tracks of traditional railroad tracks. Rolled on to a flat metal strip are the wheels of the coaster. The strip is bolted down to the track which is made out of laminated wood. The wheels of the coaster are very similar to that of a train. A wide lip is contained on the inner part of the lip. This keeps the car from falling off the side of the track. Underneath the track runs another set of wheels, which prevents the cars from flying off the tracks. • With these materials designers create The Giant Dipper at Santa Cruz hills, twists, and turns in various Beach Boardwalk, Santa Cruz, CA: directions. Not only that, they can This classic wooden coaster was even flip the train upside down. built in 1924. However, this is rare in modern roller coasters. The motion is mainly up and down. Tubular Steel Coasters • In the 1950’s, roller coasters designs changed completely with the introduction of tubular steel tracks. Tubular steel tracks consist of a pair of steel tubes. The wheels that sit right on the track are made of nylon or polyurethane. In addition to the wheels that lay on the track, the cars have wheels that run along the side and the bottom of the tubes. All of these wheels keep the car secured to the track. • The train cars in tubular steel coasters may rest on the track or attach to the The Dragon Khan, a tubular steel roller track. In a suspended coaster, the coaster at Universal Studios Port hanging trains swing form a pivoted Aventura in Salou, Spain: joint, adding an additional side to side The 4,165 feet (1,269 meters) of track in motion. In an inverted coaster, the this coaster is twisted into several hanging train is attached to the track, loops, twists and corkscrews. which gives the designer more control over how the cars move. Tubular Roller Coasters cont. • A tubular track is laid out with large curved segments unlike a wooden track which is laid out in small pieces. In a tubular roller coaster, the ride is smooth while in a wooden the ride is rough. Each roller coaster has it's own distinctive character.