BBC's Water Rocket-Vehicle Contest

jmichaelg writes: "The BBC is running a rocket contest to see who can build the fastest 2 liter water bottle propelled vehicle. The idea is you use a bicycle pump to pressurize the bottle to drive the vehicle. There are pressure limits (no more than 70 psi) so dry ice is out of the question. Gotta use a bike pump. Fastest car to go 20 meters is the winner. If you're going to play, you had better get going ... contest ends on Nov 6." Bonus points if you're riding it at the time.

Comments

turn a driveshaft instead on of pushing via jet

[Ledge]

Suppose you could generate a lower E.T. by driving wheels with the power instead of using strictly the push of the jet? 20 meters on pavement seems like its a long enough distance that you'd be coasting by the end under jet power. Perhaps you could harness more of the energy by driving wheels.
Or not. What do I know. Guess I'll have to try it and see. Incidentally, why do they limit charging it to a bicycle pump? 70 psi is 70 psi if it came from a pigs lips or an air compressor.