All: An interesting discussion about the physics of collisions. I believe this is not well understood by most people. Just a bit of my background so you know some of my credentials. I am presently completely my PhD in atmospheric physics so I hope I have at least at fundamental grasp of physics :).
First off for anyone really interested, one of the best introductory books on physics is "Fundamentals of Physics" by Halliday and Resnick. It is a first year university physics book, but I still use it for a lot of the basics. It is very well written. Concerning the transfer of speed from the clubhead to the ball...Dave T's explanations are exactly correct. The ONLY variables in a perfect collision are the clubhead velocity (for a stationary ball) and the masses of the club and ball. Acceleration is NOT a factor. It does not matter how the clubhead has aquired its velocity, only the magnitude of the velocity at the moment of impact matters. Whether the clubhead is accelerating or decelerating is not relavent. Someone suggested that this is not a closed system. At the moment of impact it is a closed system. Once the ball is on its way, a further force applied to the clubhead will indeed alter the clubhead's momentum. However, the ball will be well on its way and this will have no effect on the ball speed. Now, having said this, an interesting point was brought up. If the ball sticks on the face for a few thousands of a second (about 5 thousanths of a sec I believe) then continuing acceleration would be a factor. However, I suggest this is so small as to be negligible. I hope this helps a bit. Max
