Roller Coasters
Riding roller coasters are a summertime past time that many look forward to thrill ride type annually. The first amusement park style rollercoaster was invented in the late 1800's in the US with Australia and France following in the early 1900's. The American Eagle was my first roller coaster as an enthusiast, it was built back in 1981 containing a wooden track and at one time was the fastest and had the longest drop amongst wooden roller coasters. As far as steel tracks go, I can remember riding the Batman ride when it opened in 1992 at Six Flags in Illinois. Back then it was the first inverted roller coaster in the world, meaning that the seats are attached to the wheel carriage and the train itself runs under the track so that your feet are dangling.
Currently according to the roller coaster census report there are 5057 roller coasters in the world, comprised of 8 different types of roller coasters that are made of either a wooden or steel track. For a roller coaster to operate it is dependent on the gravitational forces that attract the roller coaster train to the track, as well as, converts potential stored energy into kinetic motion energy. It is these same g-forces that accelerate the roller coaster train which causes a change in speed that can make your stomach experience that "sinking feeling" as the coaster falls downward.
The average speed of a roller coaster is around 80mph, however speeds can accelerate to over 150mph. To achieve these fast speeds the train of the roller coaster moves along a wooden or steel track using either a chain lift mechanism or a catapult launch lift. A chain lift mechanism includes pulleys and an induction motor that builds potential energy to be later converted into kinetic energy as it moves along the track. Whereas a catapult launch lift uses electromagnets to produce 2 magnetic fields (1 on the train and 1 on the track) containing an electric current possessing the kinetic energy for motion. It is the roller coasters wheel mechanism attached to the train track that enables train movement and the friction that occurs between the wheel mechanism and track that aids in the safe movement of the train.
