Join Date: Mar 2006
Location: New England
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Umm... if you are sailing at five knots DDW, and the wind is at five knots... the apparent wind is going to be zero. Of course, this would only work if there were no friction...
However, the apparent wind at deck level may be zero, with the boat doing five knots DDW, and the wind speed a bit above five knots. The apparent wind at deck level isn't the same as the wind 20 feet above the deck level—which may be sufficient enough to move the boat at the speed of five knots.
Bernoulli's principle doesn't come into play unless the sails are generating lift. Running DDW, the sails aren't tgenerating lift, but acting as large wind breaks... and the force generated by the sails at that point is equal to the wind speed x surface area.
Rockter, Chris, you guys need to go back and study physics a bit more. BTW, wind speed is generally slower as you get lower in altitude due to the friction effects of the surface—applies to ground, water, or boat decks.
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You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.
—Cpt. Mal Reynolds, Serenity (edited)
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