Re: Tenkan and Centrifugal Force
Mike Sigman is correct. Tenkan is a turning entry into (actually alongside or behind) the line of attack, without interfering with the movement in an inertiaI frame of reference. This is "aiki"! It has nothing to do with centripetal or centifugal (which is a pseudo!) force.
The "tenkan takedown techniques" Ron refers to is more the result of gravity and Newton's 2nd Law of motion - NOT centripetal force.