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Old 11-01-2007, 10:04 PM
Sephus Sephus is offline
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Join Date: Aug 2004
Posts: 3,994
Default Re: Would this work?

[ QUOTE ]
Actually, it would work. There is force being generated on both sides of the fan, but on one side the sail is catching it, on the other side only minor air turbulence is there to resist the force.

[/ QUOTE ]

the fan is pushing the air forward. you're pushing the fan forward. the boat is pushing the bottoms of your feet forward. you're pushing the boat backward just as hard as the fan is pushing forward on the air. that's how you stay on the boat (see: newton's 3rd law of motion).

so in order to have a net forward force, the air has to push on the sail harder than the fan is pushing on the air. you're never going to get 100% of that kinetic energy from the fan to the air back into the sail.

the boat is going backwards.
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