The semester just started just recently but my teacher already gave out our final assignment... and nobody in our class has any clue how to do it. Bascially, we have to build an object that will "jump" up by itself, and 50% of the project mark is based on how HIGH it jumps. She made it clear that she wasn't interested in how long it stayed up there though. But there are certain restrictions... - no springs - no balloons - no chemistry, ie. combustion - no electronics components - nothing can be left behind, ie. no launch pad Bascially, the project is supposed to be "mechanic". Any ideas guys? Air/water pressure is a good direction but no balloons allowed and I can't think of how to use pressure without something like a balloon. Plus, the object should be fairly lightweight since this is being counted on for how high it goes. I'm thinking maybe along the lines of elastic or some kind of winding motor attached with several fan blades tilted so that if the object spins itself at a high speed (after winding it up), it would automatically fly up by itself. Do you guys follow? Is this possible? Are there any better options I haven't figured yet? Thanks guys.