Help, School Project

[icameburning]

what would be the best way to make a miniature boat out of a 20 oz. soda bottle, baking soda and 6M acetic acid?

i need it to pass the final.

[Skippy]

what would be the best way to make a miniature boat out of a 20 oz. soda bottle, baking soda and 6M acetic acid?
Interesting problem. It can rotate without harm. It sounds like the most important thing is to make sure it keeps going straight. You could put tailfins all around the nozzle, just like a rocket. But you would need more of them, because they won't all be in the water at the same time. If you can position them aft of the nozzle (farther back), that'll be more stable too. And of course they need to be waterproof.

[Richard Petersen]

What is 6M acetic acid?

[Tim B]

I know this sounds more complex, but could you build a hull then use a single-cylinder piston engine to drive a prop. The baking soda + acid combination should provide air (or CO2) at sufficient pressure, and the 'engine' could be a modified stem engine (have a look on the web). This gives normal control, and good efficiency. It would also run from a compressor.

Tim B.

[Skippy]

It can rotate without harm. ... You could put tailfins all around the nozzle, just like a rocket.
Okay, never mind that. The fins won't work precisely because the bottle is free to roll.

ICB, you could keep the boat going straight with some kind of rudder sticking into the water, far aft, just like the fins. But you do need to prevent the boat from rolling, so the rudder can work. Usually you put some kind of flotation on either side, but there are lots of ways to do that. Maybe you could look at some boats on the web for ideas.

Beach Cats (http://www.thebeachcats.com/modules.php?op=modload&name=gallery&file=index) is about sailboats, but it has good catamaran pictures.
And there are trimaran pictures here:
http://www.trimarans.com
http://www.corsairmarine.com
http://www.windrider.com
http://www.trihulls.com