What Mass is involved in the strike?
- Thread starter George_Connor
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hp12c
New
ZAP
New
Well since the ball is sitting still and the club is moving I thought it might.
And I have run into enough parked cars playing street football. Fortunaty we always had a spotter to keep the cars from hitting us.
mandrin
New
lia,
Discussions regarding “heavy hit” are a recurrent theme on golf forums. There is usually mentioning of golf clubs attached to trains or other heavy vehicles. It is indeed a rather attractive intuitive notion. Even a reputable scientist such a Mindy Blake, author of two golf books, firmly believed in the “heavy hit”. About 40 years ago he wrote:
'It is widely accepted that the critical factor in determining the distance a golf ball travels is clubhead speed at impact. This is not true. Supporters of that view do their mathematics on the assumption that the clubhead is a free-moving object colliding with a golf ball. In fact, a golf ball is not a free-moving object. It is an extension of the body, gripped by the hands, and the critical factor in determining the distance a golf ball travels is pressure applied to it or, to put this in a more scientific way, the application of force through distance.”
In another golf book - How to hit a golf ball straight, (1967) by Ike S. Hardy - equally with adamant views on the "heavy hit":
“Speed in the clubhead is NOT the power which drives a golf ball”.
“No degree of speed in the clubhead will supplant the power of swinging the weight of the body into the stroke”
TGM is also of the same school of thinking. Notwithstanding the appeal of it all, it is incorrect. The clubhead constitutes for all practical purpose a free mass for the short time interval of impact. Our intuition and reaction time are not really geared to handle the very large impact forces which are so short-lived, 0.0004 sec.
Hence the problem as posed is simplified realizing that hitting a stationary ball with a golf club or firing a ball at a stationary golf club held by a golfer or attached to a vehicle can be considered both as a collision of two masses, one moving and one stationary. The clubhead in both cases acts as a free mass during the small time interval of the collision. The hosel will add some mass but the clubhead is essentially decoupled from the golfer during impact, for both cases. Here are some calculations. Simple head-on collision is considered, no oblique angles.
mandrin
New
To complement my previous post. There are two notions associated with the idea of a "heavy hit", similar but not quite the same.
1) The first is more concerned with producing forces. The believe that one can resist deceleration of the clubhead through impact. Hence that a golfer can exert enough force onto the head through impact to reduce clubhead deceleration.
2) The idea that a slow deliberate swing with a firm grip will produce more ball speed than a quick free flowing golf swing through the ball. .This implies that the golfer can somehow add rather substantial mass to the clubhead.
Both notions are incorrect but I wanted specifically to add some more comments regarding the believe of increasing the effective striking mass of the clubhead.
1) The first is more concerned with producing forces. The believe that one can resist deceleration of the clubhead through impact. Hence that a golfer can exert enough force onto the head through impact to reduce clubhead deceleration.
2) The idea that a slow deliberate swing with a firm grip will produce more ball speed than a quick free flowing golf swing through the ball. .This implies that the golfer can somehow add rather substantial mass to the clubhead.
Both notions are incorrect but I wanted specifically to add some more comments regarding the believe of increasing the effective striking mass of the clubhead.
lia41985
New member
Hey mandrin,
Speaking of oblique...would you mind just addressing the clamping analogy directly? I never brought up mass, even once. By the way, it seems to me that using non oblique collisions as models for golf impact seems highly impractical to me. Far too idealized.
Thanks,
lia
Speaking of oblique...would you mind just addressing the clamping analogy directly? I never brought up mass, even once. By the way, it seems to me that using non oblique collisions as models for golf impact seems highly impractical to me. Far too idealized.
Thanks,
lia
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faux_maestro
New
I thought the clamping analogy is explained by the thought of the club acting as though it is detached from the shaft, no? It doesn't matter what is happening beyond the clubhead and say the last 6 inches of the shaft going into the clubhead. I'm not a scientist and can't show the proofs but this is what I think I've heard the scientists say.
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faux_maestro
New
I realized that too, sir. But I also realized the collision would be substantively different between the clamped and non-clamped examples (i.e. significant). Something worth reporting? Maybe. A great discovery? Maybe not. Intuitive? Well, who are you?
I thought this would be along the lines of "adding mass" and "the heavy hit" and "lag pressure" and "resisting deceleration". Am I wrong?
As for who I am, I'm just some dude who is crazy about golf.
birly-shirly
New
As far as I understand it, it doesn't matter to any practical extent for this discussion whether the shaft is swinging free, held by a golfer, or clamped. Impact and separation happen so fast that there isn't time for the shaft to flex or apply any significant reaction force to the ball in excess of what's brought by the free-swinging clubhead (+6" of shaft) and its momentum.
lia41985
New member
If you wouldn't mind, please, try in some way to run the experiment and tell me what you observe. I'd rather have your reflections on that than your preconceived notion or theoretical regurgitation.
birly-shirly
New
Sir, if you wouldn't mind I'd rather have you just wind in your neck a tad and save me the trouble of adding you to my "Ignore List".
I haven't exactly noticed empirical data coming out of your ass. Just some reheated all-purpose high school pseudo-intellectual debating point about Popper.
You reckon you "realized the collision would be substantively different between the clamped and non-clamped examples". No you didn't, you theorized that they might be different. And reputable experts say you're wrong.
So might I suggest that you run some experiments, or better still, find someone who's qualified to do so, and report back.
I haven't exactly noticed empirical data coming out of your ass. Just some reheated all-purpose high school pseudo-intellectual debating point about Popper.
You reckon you "realized the collision would be substantively different between the clamped and non-clamped examples". No you didn't, you theorized that they might be different. And reputable experts say you're wrong.
So might I suggest that you run some experiments, or better still, find someone who's qualified to do so, and report back.
lia41985
New member
You would be troubled by doing so though, right?
Love and the love of knowledge is so unrequited. They even create self-deception.
Hate know-it-all, love-it-all, lia.
By the way, your so-called reputable experts didn't run the experiment.
I have.
Unclamped the ball/club pair "react" very differently to the collision.
Duh.
Love and the love of knowledge is so unrequited. They even create self-deception.
Hate know-it-all, love-it-all, lia.
By the way, your so-called reputable experts didn't run the experiment.
I have.
Unclamped the ball/club pair "react" very differently to the collision.
Duh.
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birly-shirly
New
You won't mind providing the conventional "methods statement" for your research? I'm looking forward to learning how you accurately fired a golf ball at 100mph into the centre of the clubface.
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