Pat, What you are saying makes sense to me intuitively, but it can only affect the impact for the very brief time of the collision (measured in thousandths of a second probably). If the clubhead is still accelerating at the beginning of the impact (vs. decelerating and/or constant), then it follows that it will be traveling faster after impact. This should translate to higher ball speed, but I'm guessing it will be a minimal increase. This can be proven if we can measure the clubhead velocity immediately pre and post-impact with the ball, as well as ball speed after impact. If higher ball speed correlates with higher post-impact clubhead speed, you have your answer.
Tedd -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, October 14, 2004 10:47 AM To: [EMAIL PROTECTED] Subject: Re: RE: ShopTalk: long drive Just to reinterate - conservation of momentum applies to an isolated system, where no external force is appled to either object in the collision. If the USGA air cannon fires a ball at a fixed driver's face, conservation of momentum applies. If you're increasing the force applied to the clubhead at it impacts the ball, that increase in force upsets the isolated system principle, and it's conservation equation(s). But, I'm sure we'll see that I'm wrong according to Dave T...... Pat K
