Hey, there. I'm in highschool physics, so hopefully this problem will alow you guys to think creatively without hurting your braincells. We're supposed to build a car out of index cards/file folders, tape, glue, straws, paperclips and rubberbands only. The car must go at least 20 ft and carry its propulsion system (i.e. can't be pushed). Anyhow, I've come up with some designs, but the best propulsion system I can think of is a propeller. I'm sure it'll work fine, but it's kind of boring! Any creative car ideas? Any propeller ideas that will help our car go a long distance are welcome, as well. The entire object is to get it to roll/fly/whatever as far as possible, provided it starts/ends on the ground!