At 11:06 PM 01/04/2000 -0800, Scobie Puchtler or Sarah Felstiner wrote:
>In reaction to a submission about a landsailer that could make speeds of
>120mph, Tracy recently wrote:
I should note that the car in question hadn't reached these speeds as of
the time the show was filmed. It was hoped it would go that fast, though.
> While sailcraft are often seen as 'simply being pushed
>along by the wind', this is only the case when travelling downwind. When
>travelling more like perpendicular to the wind, on a 'point of sail'
>referred to as a 'broad reach', sailcraft become a rather sophisticated
>balance of vectors, taking wonderful advantage of lift over the foil section
>of the winglike sail to produce speeds potentially surprisingly higher than
>the wind itself
Well, that makes some sense. I can see that, with the wind coming from the
side, the sail is under a constant force from the side, which can being
redirected to push/pull the craft forward, no matter how fast the wind the
craft is moving. Since F=MA, the boat/car should continue to accelerate
until the frictional or drag forces equal the force on the wing/sail.
OTOH, if going directly downwind, the force on the wing/sail would drop to
zero as the craft approached the speed of the wind. Is that close to being
correct?
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