The Different Rides in an Amusement Park by John Joseph B. Reyes

Imagine spinning a ball on a string around you. The ball is traveling in a circular path. But Newton’s first law states that an object in motion stays in motion and that motion is in a straight path, not a circular path. Since the ball is traveling in a circular path, an outside force must be acting on the ball – that force is the string. The string is pulling the ball back toward you, acting as the centripetal force. Centripetal means “center-seeking” and is the force that is acting on the carousel. The platform upon which the horses and people are riding is the centripetal force that keeps them traveling in a circular motion just as the string was the centripetal force for the ball. As long as the ride is moving slowly enough, the centripetal force of the platform can keep everyone and everything on board.

In theory, if the carousel starts moving really fast, centrifugal force* (“center-fearing”) takes over and breaks the hold the platform (centripetal force) had on the riders and the riders would fly off. *Centrifugal force is actually not a real force. If the centripetal force that pulls an object into the center stops working (e.g. the string breaks), then it is the object’s inertia that takes over and sends the object traveling in a straight path. You can test this outside by spinning a ball around you and letting go of the string. If centrifugal force was a real force, the ball would move straight away from the center at the point where the string was let go. But it doesn’t. Instead, the ball follows its path of inertia and moves in a straight path that is tangent to the circular path. In Enchanted Kingdom, one of the rides is Jungle Log Jam, During the descent of the log from the top of the rail, why did you pitch forward when the log slowed down?

The world’s tallest roller coaster is the Kingda Ka at 456 feet, it also has the biggest drop at 418 feet, and goes from 0 to 128 mph in just 3.5 seconds. The First Law of motion is: An object at rest remains at rest, and an object in motion tends to remain in motion. The roller coaster does not move at first until hauled to the top of an incline. The roller then accelerates and remains in motion for several rises and falls, slowed and then accelerated again by gravity, but losing energy only to friction with the track and the air. Once this momentum is used up, it again has to be pulled to the top of an incline, and start down again. To control its speed, and at the end, brakes have to be used to slow it down. Additionally, riders in the car will experience an apparent increase or decrease in their body weight at the top and bottom of inclines. Their forward momentum will push them down in their seats at the bottom, but as they crest each hill, their bodies will attempt to continue upward, out of the seats. For this reason, a restraining bar is necessary.

The second law is: The acceleration of an object depends on the mass of the object and the amount of force applied. When a roller coaster goes down a steep hill, gravity makes the roller coaster speed up, and going up a hill, it slows down. The higher the incline, the greater its acceleration and the greater its speed becomes by the time it reaches the bottom.

The third law is: Whenever one object exerts a force on a second object the second object exerts an equal and opposite force on the first. Since a roller coaster is on a ramp, the ramp has to support the weight of the roller coaster, especially when it turns it back up against gravity at the bottom of each incline. The rollers on each car also prevent the cars from leaving the track on turns, by exerting a controlling force using the sides and upper half of the track.

Modified from:

http://www.hometrainingtools.com/amusement-park-physics/a/1411/ http://www.slideshare.net/pontron25/three-laws-of-motion-1#btnNext http://www.complex.com/rides/2011/06/the-worlds-50-best-roller-coasters/kingda-ka http://wiki.answers.com/Q/How_do_Newton’s_three_laws_of_motion_relate_to_a_roller_coaster Pictures from: virtualjournals.net