The entire concept behind a roller coaster is that it utilizes gravity to make massive amounts of potential energy before releasing them in the form of kinetic energy. In order to create the first and greatest reservoir of potential energy, the cars make their way up the first hill. This ascent is usually initialized with the chain lift, which acts as a conveyor belt to bring the coaster cars to the peak of the hill. At the top, the car's potential energy is as high as it will be for the rest of the ride.
After the chain lift disengages, gravity takes over and acts as the source of energy acting upon the coaster. As the cars descend, their potential energy is lost and in return they gain kinetic energy. Upon reaching the bottom of the hill, almost all of the potential energy is gone. However, on it's way over the next hill, the coaster loses some of its kinetic energy and gains some of its previous potential energy. This continues till it reaches the crest of the second hill
at-which-point the process begins again.
This link has an interactive image/video thing that can help to better explain kinetic and potential energy: http://science.howstuffworks.com/engineering/structural/roller-coaster3.htm
Because an object in motion tends to stay in motion (Newton's first law of motion), the coaster will maintain a forward velocity even as it climbs up the hills, working against gravity. This makes it possible for there to be any variation in the slope of the track, such as the swerves, hills, and loops.
Here is a cool picture that displays forces that I'm not going to talk about.
Due to friction between the train and the track, as well as the train and the air, the coaster continually loses kinetic and potential energy. For this reason, the hills decrease in size as the cars make their way through the ride. Eventually, the ride slows down to the point that it is unable to move forward any longer. By now the tracks have lead back to the beginning of the ride and the brakes are activated.
Sources:
- science.howstuffworks.com, "How Roller Coasters Work", Tom Harris
- Common sense and experience
I'm not actually sure what his question is for us on here. But something I think is cool are the new air coasters that act kinda like an air hockey tabel to reduce friction. My question is what is another way we could reduce the friction on the roler coaster allowing for less decrease of the humps.
ReplyDeleteIf the car has it's greatest potential energy at the very first hill, can it gain this potential energy back if there is a chain lift halfway through the ride that takes the car back to its original highest height?
ReplyDeleteIs there the same force in every car of the roller-coaster? I've always been under the impression that the last car on the ride has the most force due to the fact that it goes through the loops and the turns at a higher velocity (going over the first drop the back goes the the entire drop quicker, as the front obtains that speed at the bottom). I've been on a rollercoaster actually once that was more like a bobsled. It slid on a slide compared to the wheels on the tracks like a normal ride.
ReplyDeleteMy question is since gravity is always "pointing" toward the center of the earth, how is it determined how fast the roller coaster has to go to create enough centrifugal force to essentially not fall off the tracks during a loop?
ReplyDeleteShane-
ReplyDeleteYes this is possible! Since the car is being taken back to its original height, assuming that the second chain lift takes the cars as high as the first chain lift, then all of the potential energy that the rollercoaster had at the top of the first chain lift will be the same as at the top of the second.
As an avid roller coaster fan, do you think it might be more efficient to have the biggest hill at the start of the ride, or completely use the station and gravity to start the ride downhill first. (reason I ask is my hometown park of Kennywood has three rides that do so).
ReplyDeleteIf the cars were able to do this at a large enough height into a valley at first, could eliminate an powered hill altogether using potential gravitational energy?
-Jason
Wow, I just answered every question comment on here and tried to post comment. It told me I had chosen to post on the wrong profile and then deleted all my answers. :(
ReplyDelete