A python question here, or more strictly maths; but everyone here is more responsive than dedicated forums!
If i am applying a force over a distance, to move object X to B, i am using the vector between them as the force, and using a constant to control the speed.
However, this isn’t the best method. How could i move an object to a point using physics that works with some friction, and falls off as it gets closer.
In other words, it needs to get to point B quite fast, but using the physics engine and not loc / vector movement.
I explain and write a falloff function for the application of force (based on distance) in my explosion physics tutorial.
You can start watching from this point: http://www.youtube.com/watch?v=KdA7f421QWI#t=11m40s
I ended up using setlinv instead of applyForce which fixed it as it wasn’t adding on top of previous force -.-
However, by using the square of the magnitude of the vector i acheived better results. I would have liked to have used your method, and it crossed my mind to use a function, however, the movement occurs from current position to B and not from A to B.