Sail horsepower vs wind force?

[tommc]

I am interested in calculating some sort of approximation of horsepower knowing force exerted on a sail. I am calculating force using:
F (lbs / sf) = C x V(knots)^2
Where: V = wind velocity
C = constant = 0.004.
Does anyone know a reasonable simple formula that would approximate the horsepower from this?
Thanks

[tspeer]

Power = Force * Velocity

[tommc]

Thanks for the advice. I actually was thinking of that calculation but it ends up with HP going up as the cube of the wind velocity which I didn't quite want to believe was the case. So one more dumb question here. Does the available horsepower actually rise as the cube of wind velocity?

[tspeer]

Sure, until you reach the stability limits of the craft. Then the force must stay constant (to maintain constant moment), so the power only goes up linearly after that.