Yoda - I think that this debate is getting unnecessarily complicated and unproductive.
I think of it this way.
The orbiting ball receives all its energy via the string. The source of the energy is the hand moving in a circular manner. The energy travels
outwards from the hand to the orbiting ball- along the string. That energy is required to perform two roles - i) keep the ball moving at a constant speed and ii) keep the ball moving in a circle at its constant surface speed.
When a orbiting object travels at a constant speed it may not need much energy to keep it moving at a constant speed (if there is little frictional resistance to its movement in space), but it requires constant energy input to constantly change direction (in order to move in a circular path). In other words, although the orbiting ball is traveling at a constant surface speed, it needs a constant source of energy to
centripetally accelerate (accelerate towards its center of rotation). That energy comes from the hands and it is transmitted via the connecting string.
If you understand that viewpoint - then door 1 is correct.
Door 1
Behind Door #1:
"The CP pull is exerted by the hands and the pull is along the length of the string . . . "".
However, one can look at this orbiting ball scenario from a different perspective, and look at the scenario from the orbiting ball's perspective. Then door 2 applies.
Door 2
Behind Door #2:
"The string transmits the CP pulling force from the ball to the hands (inwards pull towards the center)."
The ball experiences a centripetal force that pulls it towards its center of rotation. The pull is in the direction of centripetal acceleration. The ball doesn't know where the CP force is coming from - it only knows that it is being pulled by the string, and it happily thinks that the string is providing a CP force that keeps it a state of constant centripetal acceleration.
However, ultimately the centripetal force that keeps the orbiting ball traveling in a circle is derived from the orbiting hand's movement in space, and the energy
must travel from the hands to the ball - travels outwards along the string. Some of that energy makes the ball move, and some of that energy supplies a centripetal force that
conceptually travels back down the string and keeps the orbiting ball from flying into space. I find it meaningless to think of the string providing that CP force - because the string doesn't really create energy. It only allows part of the energy created by the orbiting hands to be translated into a CP force that pulls the orbiting ball towards the center.
I actually try to avoid using the terms "centripetal" and "centrifugal" in my thinking about the golf swing. It gets way too semantic and too complicated. The idea of a centrifugal force is merely a
conceptual idea used to see the CP force as being balanced by an equal and opposite force. Many people state that it not really a force - because it cannot exist alone. I am sympathetic to the idea that it is not useful to conjure up the idea of a CF working in the opposite direction to a CP force.
I much prefer to think in terms of vectors of movement and force, and not use the terms CP force or CF force if I can avoid the terms. That's why I like nmgolfers explanation of the release phenomenon.
See -
http://perfectgolfswingreview.net/Ne...%20Science.htm
When I think of the golf swing, I never think of a rotational center. I simply see different body parts moving in 3-D space, and I simply think of the forces that move those body parts and their vector of movement. I think the same way with respect to the golf club. The golf club is only moved by pull-forces or push-forces exerted at grip level.
Jeff.
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