[BerntR]

Jeff,

No problem with your demo.

There is a difference between actively driving the hands in a circle and merely let the hands respond to a centripetal force. The first one accumulates energy, the second only preserves it.

I don't think I have said that centripetal force is required to store energy. (At least not in this thread But for those of us who prefere the traditional swing-like golf stroke I'm afraid it is unavoidable.) My main point about the centripetal force is that it doesn't power the golf swing. It is a deliberate drive of your hands in a circular manner that powers the swing in your video.

The release sequeence (in your demo) also has a side that deals with redistribution of energy that I haven't addressed. As you know a good golf swing is typically dominated by body rotation in the early down swing. Then the body slows down as the arms take over. Then the arms slow down as the club take over. This overtaking action redristributes some of the velocity energy from the body to the arms and further to the club. And this plays a part in generating clubhead speed. But if you look at the club in isolation, you still need the tangential forces to make this transfer of energy happen.

Some of the tangential forces will come from mass that already moves in a circular manner (hands, arms, body). This mass-velocity will resist slowdown.

The release action is also similar to a gear shift in a car. It enables you to apply a significant tangential force - and build incredible swing speed while working at close to optimum body speeds.