There is a lot of physics that is involved in the loops of roller coasters. One of those things would be the energy transformations that occur, when the coaster is getting ready to enter the loop it has 100% kinetic mechanical energy (KEm), when the coaster is halfway to the top of the loop there is 50% kinetic mechanical energy and 50% potential gravitational energy (PEg). When the coaster is at the very top of the loop, there is 100% potential gravitational energy, the coaster stops moving for about a second. The coaster then goes down the loop and when it is halfway down there is again 50% KEm and 50% PEg. When the coaster finally reaches the bottom of the loop, the energy goes back to 100% KEm. Throughout this whole thing, the total energy remains the same, as seen below.
Want to play a cool game? Click on this link and have a blast! :) http://www.agame.com/game/rollercoaster-rush.html
Links:
http://ffden2.phys.uaf.edu/211_fall2002.web.dir/shawna_sastamoinen/Clothoid_Loop.htm
http://science.howstuffworks.com/engineering/structural/roller-coaster7.htm
http://ffden2.phys.uaf.edu/211_fall2002.web.dir/shawna_sastamoinen/Clothoid_Loop.htm
http://science.howstuffworks.com/engineering/structural/roller-coaster7.htm