Cannons

http://www.youtube.com/watch?v=bSdHUOBNm68
Is it bad if that's the first thing that came into my mind when the teacher said we were gonna make a cannon?

So we were to make a cannon out of 5 pop cans. Three for nuzzle, two for base, and a pair of styrofoam cups for a projectile. It'll be fueled by ethanol. Our goal was to make the projectile travel as far as possible.

http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html
According to this site, projectiles travel farthest at 45 degrees, assuming there's nothing in the way.

We also learned that according to Newton's Law, acceleration = force/mass, so we'd want to make the cannon heavy as possible if we don't want it to fly away when we launch it.