|MadSci Network: Physics|
Well let's do better than words!!! Here is a picture I reproduced from "The Physics of Sports" edited by Angelo Armenti Jr.
The balance of forces for a yacht sailing to windward. HSF denotes the hull (plus centerboard or keel) sode force, HD the hull drag, SLF the sail lift force and SD the sail drag. the angle between the boat's course and the wind is A, C is the drag angle and B is that of the the sail. It can be shown that A - B = C in the case of balanced side forces.
To figure out the force vectors for other wind orientations, rotate the wind to a different direction and try redrawing the vector diagram.
Tom "Little Buddy" Cull
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