Calculating S Using Fm in a Magnus Force Equation

[dirtybageled]

what is s in this equation and how what equation do I need to figure out what S is
Fm = S (w × v)

Where:
Fm =the Magnus force vector

w= angular velocity vector of the object

v=Velocity of the fluid (or velocity of object, depends on perspective)

S= air resistance coefficient across the surface of the object

 

[user56]

learn to rearrange the subject of the equation to S.
The magnus effect might be because of inertia.