Baarb wrote:While i suppose this is a fairly theoretical discussion,
Yes, the model ignores some effects that may become quite important for large values of alpha. Besides, it ignores stability. If I'm leaning forward 10 degrees and the wind suddenly dies, I move one foot forward and regain balance. Not so easy if I'm leaning 45 degrees into the wind. Even such a simplified model, though, is useful in understanding what goes on.
Baarb wrote: I would think that there's a limit to how much you can physically lean forward and still have your feet sticking to the ground.
Indeed there is--even according to the simplified model. If the angle and the coefficient of friction are such that tan(alpha) > mu, then your feet no longer stick to the ground.
Baarb wrote: E.g. at 65 degrees or so you would have to be balancing on your toes or the front end of your boots, the area of which is pretty low,
Friction is a complex phenomenon, but in first approximation Coulomb's Law applies, according to which the friction force is independent of contact area.
Baarb wrote: not to mention your centre of gravity is no-way near them.
True, but that is accounted for in the equation for v that hansw posted at the beginning of this thread.