[Sonic_Doom]

Spot on annekin!

"While Centrepetal force pulls it in a circle...Centrifugal force changes the length of this string..."

Centripetal force acts on the rock. Centrifugal force acts on the string. For other contributors, remember that these words aren't magic. Centrifugal=away from the centre. Centripetal=toward the centre.

I can't argue beyond this explanation. In the case of the TGM model the string length (radius) is from shoulder the clubhead and it lengthens dramatically from start down to impact. Like a flail with the wrist as the thong.

Is this close to correct? No physics degree over here,,

CW