[golf_sceptic]

Before this discussion deteriorates any further.

In response to my comment about centrifugal force Yoda wrote:

Nevertheless, the concept as he defined it in the Glossary -- "The effort of the Swinging Clubhead to pull the Primary Lever Assembly (Left Arm and Club) into a straight line" -- is the essence of the Physics of Rotation. As any kid who has ever whirled a rock on a string could tell us.

Unless I am very much mistaken, yoda was suggesting that centrifugal force is responsible for both the "pull" on the primary lever, and the tension in the kid's string.

As a result, I explained the forces involved in the kid and the rock example

In the rock on the string example the rock is affected by only one force. That is centripetal force and it is what causes the rock to follow a circular path.

As a result of the string pulling on the rock, the rock pulls on the string with an equal and opposite force. That is the centrifugal force.

Going further, the boy pulls on the string (centripetal) and the string pulls on the boy (centrifugal).

To balance the pull from the string, the boy leans back ever so slightly and uses gravity to balance himself.

If we can get past this point, I'd like to discuss the validity of the other part of yoda's quote from a physics point of view. The point I'd like to stress is that the centrifugal force does exist, but affects the kid (via the string) and not the stone. Does anybody need further clarification of the kid and the rock?