Physics Rollercoaster-- Simple electric circuit Hi all, I'm working on my physics rollercoaster project for grade 11 and I need a simple electric circuit to incorporate into it for more marks. At first I was thinking a circuit to bring the ball back up a hill when it reached the bottom but then, to do it, it got more and more complicated to make it work for a certain amunt of time, stop... etc.. then im thinking: what about some sort of LED circuit? My idea now is to somehow have the steel bearing ball (at hte very end of hte rollercoaster, when i dont mind slowing the ball down) run through some sort of.. pathway of aluminum foil that creates a bunch of circuits to LED's that line the last... 3 feet? maybe? of track? along hte side. I have a bunch that I happened to buy on Ebay and they'd do fine. I'd only use maybe... 12 in total along those 3 feet, and id want them to light up closely in relation to where the bearing is. My question in this is obvious: will it work? or will i have to have the ball slow down a LOT in order for it to create a circuit long enough for hte lights to shine? Unless anyone else has some other SIMPLE circuit sugestion?