ball velocity

Question
QUESTION: Is there a difference in ball velocity if hit by a club face moving at 90 mph at  contact and accelerating, and a club face moving at 90 mph but decelerating?  Is there impudus placed in the equation based on rate of change?

ANSWER: Hi Dolen,

There would not be an appreciable difference in the speed of the ball unless the acceleration amount were quite large (not likely in a typical golf swing). The emphasis of "accelerating through the ball" promotes a good club head path and more club head speed. Once the club contacts the ball, the resulting ball speed depends on the speed of the club, not whether it is accelerating or decelerating. Hope this helps.

Please visit and patronize my website:
http://www.probablegolfinstruction.com

Best regards,
Ken Tannar

---------- FOLLOW-UP ----------

QUESTION: Where am I going wrong: My brother in-law has shoulders and arms like a guerilla, he swings the club with arms only no body and in no stretch of the imagination can he generate swing speeds that can explain his 250 yard drives.
He grips the club with a death grip and has little or no follow through.  Heres what I think is going on:

If you place the golf club head and shaft on a scale, that weight becomes part of the equation Energy = mass * velocity squared.   That is the equation I would expect if the club head were neither accelerating or decelerating at impact with the ball. However, If you place the club head and shaft on the same scale and apply downward pressure on the shaft the resulting "weight" could be several times the resting weight and that weight becomes part of the equation.  Is there energy transferred into the club head from body strength as well as swing speed??

Thanks again
Dolen

Answer
Hi Dolen,

Scientists did an experiment years ago which is published in the book, "Search for the Perfect Swing". It involved a Driver which was had a freely moving hinge between the shaft and the clubhead. A golfer would not be able to add any force to the ball at impact because the hinge would rotate. When they hit golf balls, they took high speed pictures at impact and learned that the hinge did not unhinge while the clubhead was in contact with the ball. It was as if the clubhead was not connected to the shaft at all.

Since then, it has been accepted that only the speed of teh clubhead and the mass of the clubhead influences ball speed.

You can get a copy of the book by clicking on this link. It's a great classic for those that want to know the science  behind golf.
http://www.amazon.com/gp/aws/cart/add.html?SessionId=103-4122003-3624616&Subscri

Your brother-in-law hits it long because he produces high clubhead speed with his swing. Strong people are able to do this with shorter swings than weaker people. Of course, a weak person can produce high speeds as well if their technique is efficient.

No appreciable energy is transferred into the clubhead from the body at impact.

Hope this helps.

Please visit and patronize my website.
http://www.probablegolfinstruction.com

Best regards,
Ken Tannar