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How Stuff Works:
Roller Coasters

5-29-10

Roller coasters are steep, sharply curved railways with open passenger cars that are operated at incredibly high speeds and used as rides in amusement parks. These heavy powered machines cause great fun and excitement. But have you ever questioned yourself how they work? Roller coasters are much more than a fun ride; they are an incredibly importantpart of the world of physics.
“Roller coasters have no engine or source of power of their own, but they are mostly powered by momentum and gravity”, Tom Harris, contributing writer. Roller coasters are lifted by a chain that runs up the hill under the roller coasters track, when the roller coaster is lifted up, momentum builds up. The chain is tied up in a loop, which is around a gear at thesummit of the hill and also at the bottom of the hill; the bottom of the hill is powered by a motor. This turns the chain loop so that it moves continuously up the hill, the coaster cars grip onto the chain, and roll to the bottom of the hill, once the chain is hooked it pulls the coaster to the top of the hill, and once reaching the top of the hill, the coaster cars are released.
“A rollercoaster is continuously changing between kinetic and potential energy”, Melissa Mayntz, contributing writer. When the roller coasters gets high in the air the roller coaster has potential energy, and when you are going lower down the hill the potential energy changes to kinetic energy, gravity applies a constant downward force on the coaster cars. The coaster tracks control the way the coaster carsfall. If the tracks slope down, gravity pulls the front of the car to the ground, and causes it to accelerate. When the tracks slope up, gravity applies a downward force on the back of the coaster, which causes it to decelerate.
The coaster car will always maintain a forward velocity, even if it is moving up the track, opposed to the force of gravity. When the roller coaster is lifting up one of thesmaller hills that follow the initial lift, the kinetic energy coverts back to the potential energy. The acceleration is also always changing; in many roller coasters, the hills decrease as the coaster is moving along the track. The total energy stored built up in the lifted hill is progressively lost to friction between the train and the track, and also between the train and the air. When thecoaster cars drift to the end of the track, the energy stored is almost empty. When one reaches this point, the train comes to a stop or can also be sent up the lifted hill for another ride.
“On earth, gravity is always pulling everything toward the ground, by pulling downwards and upwards, the upward pressure pushes you upward to your feet”, Tom Harris, contributing writer. In a roller coasterride, gravity always pulls straight down. Acceleration is also acting on you during the ride, when one is riding at a constant speed; one feels the downward force of gravity. But as the car speeds up or slows down, one feels pressed against the seat of the restraining bar. This occurs because your inertia is separate from that of the coaster car. Every force acts on one’s body in different ways. Whenthe coaster speeds up, the seat in the cart pushes you forward, accelerating your motion. When the cart slows down, your body naturally wants to keep going at its original speed. The harness in front of you accelerates your body backward, slowing you down.
Roller coasters change acceleration and their position to the ground constantly, which makes acceleration and gravity interact in manyinteresting ways. When you plunge down a steep hill, gravity pulls downwards while acceleration force seems to pull you upwards. In a particular rate of acceleration, the opposite forces balance each other out, which make you feel weightless. If the roller coaster accelerates downwards fast enough, the upward acceleration surpasses the downward force of gravity, this makes you feel like you are being...