Effective striking mass of clubhead

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In the thread ‘A Helping Hand” the discussion gravitated around the idea of resisting impact deceleration.

Several times there was mention of a heavy hit, dragging a wet mop, swinging slow and heavy, getting the body into the swing.

There are really two notions intertwined, -1- applying torque and -2-increasing the effective mass of the clubhead.

However, these two notions don’t quite stand for the same thing.

-1- A golfer can be convinced that he can resist impact deceleration by applying torque to the club shaft using his muscles.

-2- One can also compare a very beefy golfer with a very light weight golfer both developing the same clubhead speed at impact. Many if not most golfers intuitively feel that the heavy golfer will get more distance.

Let’s delve a bit into the second option.

We probably all have read posts which are about a club attached to a train or heavy vehicle and a tiny girl golfer both striking a ball with the same clubhead speed.

This translates very vividly the very strong intuitive notion of almost all golfers, convinced that one can somehow increase the effective striking mass of his clubhead.

TGMers are quite familiar with this notion. However does it correspond to reality? ;)
 
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bts

New
a & m

What matters are acceleration and mass.

During the swing, when the shaft is stressed, it feels heavier and has more "effective mass".

During the swing, when the state of shaft-stressing is sustained, it's being accelerated.

The more the shaft is stressed (or "heavier"), the more the effort is needed to sustained (or to accerelate) it, which translates to power (or ball distance).

The secret of golf is "lag".

For some reason, I prefer to make it heavier ("lag"), instead of faster ("throwaway").
 
Rotating Mass

This translates very vividly the very strong intuitive notion of almost all golfers, convinced that one can somehow increase the effective striking mass of his clubhead.

Mandrin,
Back in my motocross racing days, if we were nosing over to much after a jump we would give the motorcycle some gas to get the rear wheel spinning which had the effect of increasing it's mass, thus increasing the "weight" of the back of the motorcycle. Is there any correlation between the spinning rear wheel and the golf club as it is swung?

Jim S.
 
No such thing as "Effective Mass"

What matters are acceleration and mass.

During the swing, when the shaft is stressed, it feels heavier and has more "effective mass".

During the swing, when the state of shaft-stressing is sustained, it's being accelerated.

The more the shaft is stressed (or "heavier"), the more the effort is needed to sustained (or to accerelate) it, which translates to power (or ball distance).

The secret of golf is "lag".

For some reason, I prefer to make it heavier ("lag"), instead of faster ("throwaway").

I've seen your posts elsewhere, and I know you know more than you're letting on. As you correctly state, it is all about mass and speed at impact. The mass of the clubhead and shaft don't change during the swing. The feel in your hands may change, and "heavy" may be what you feel, but the club weighs the same at all points in the swing. The equation 1/2 m*v^2 tells you the story. You could have an "equivalent" mass that when swung slower or faster would generate the same impact energy, but one speed, one club and one mass have only one level of energy when it impacts the ball. Preparation for impact and maximizing the speed of the clubhead have everything to do with maximizing the kinetic energy of the club assembly, but nothing to do with changing it's mass. This may translate to a certain feel that you and many others have characterized as "heavy", but it has nothing to do with weight, or striking mass of the clubhead. The "heavy" feel is related to your resistance to the inertia of the club assembly trying to fly off the circle you are trying to keep it on. In a sense, "heavy" means longer, in that you delay the release longer, and the longer delayed, the faster the club must travel to reach the ball as the club assembly travels around the small end of the "endless belt" . So, "heavy" realy means faster clubhead speed at equal mass, and thus higher striking energy than a less efficient application of the swing.

Think we can get to 150 posts on this one too?????

G2M
 
Newton’s 3d law, action = reaction

[size=-1]Mandrin, back in my motocross racing days, if we were nosing over to much after a jump we would give the motorcycle some gas to get the rear wheel spinning which had the effect of increasing it's mass, thus increasing the "weight" of the back of the motorcycle. Is there any correlation between the spinning rear wheel and the golf club as it is swung? Jim S.[/size]
Jim,

When stepping on the gas pedal the motor exerts a torque on the rear wheel. The wheel in its turn exerts a reaction torque on the body of the bike.

On the ground this will tend to lift the nose only since the rear wheel can’t get down. In the air there is no such restriction and the rear can go down.

Hence you are not increasing the effective mass of the rear wheel, instead you are within the system ‘wheel – body of bike’ creating a torque and a reaction torque.

Swinging a golf club in the down swing does not increase its mass but instead definitely its kinetic energy and momentum.
 

bts

New
effective weight and shaft flex

How much weight added to the clubhead is needed to bend a shaft 1 inch down when hold still horizontally at the grip end?

How about 2 inches down? 3 inches?

The shaft loaded and sustained by Trovino or long hitters half-way down is even more than that. That's heavy!!! Real heavy!!!!!
 
[size=-1]What matters are acceleration and mass.

During the swing, when the shaft is stressed, it feels heavier and has more "effective mass".

During the swing, when the state of shaft-stressing is sustained, it's being accelerated.

The more the shaft is stressed (or "heavier"), the more the effort is needed to sustained (or to accerelate) it, which translates to power (or ball distance).

The secret of golf is "lag".

For some reason, I prefer to make it heavier ("lag"), instead of faster ("throwaway").[/size]
bts,

g2m said it very eloquently in his post. I just like to stress also that I am not after what occurs during the downswing but rather during impact itself.

What is you reaction to the frequent posting on various forums of the ‘train girl’ comparison? Is there a different effective mass at work in each case at impact?
 
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effective_mass_%203.gif


To make sure that everyone is on the same wavelength I have illustrated the situation with a simple figure.

Does a heavy golfer have the advantage of a larger effective clubhead mass, M+dm, relative to a very light person, when both arrive at impact with the same clubhead velocity?

Hence the question is not what you do or feel doing the downswing but rather if the larger body mass of a heavy golfer translates into a larger effective striking mass at impact compared to a tiny skinny golfer.

Biffer, with a PM, just made an excellent suggestion to link matters to an Iron Byron.

Indeed this way nobody can go astray about what one feels since as far as I know Iron Byron does not have any. ;)

Hence the question now becomes: Would a heavier Iron Byron hit it farther than a lighter one, when producing same clubhead velocity at impact?
 
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A faster spin of a wheel increases its 'stability' in the same way any wheel is harder to move sideways when it is spinning - the principle of the gyroscope! So the bike would perhaps hold its position with more stability during its air time? Not knowing the sport, but only the physics of the gyroscope effect - (many are used in boats, satellites, airplanes, cars, etc. for stabilizing the crafts or instruments...) And a heavy bike wheel would have a LOT of stabilizing resistance to twisting, fer sure!
 
You're going to make my brain hurt again...

effective_mass_%203.gif


To make sure that everyone is on the same wavelength I have illustrated the situation with a simple figure.

Does a heavy golfer have the advantage of a larger effective clubhead mass, M+dm, relative to a very light person, when both arrive at impact with the same clubhead velocity?

Hence the question is not what you do or feel doing the downswing but rather if the larger body mass of a heavy golfer translates into a larger effective striking mass at impact compared to a tiny skinny golfer.

If you equalize actual clubhead mass and clubhead speed, then NO, and NO, (at least to any significant degree).

Let's suppose Hefty Harry outweighed Tiny Tina by 200 lbs, and that he was able to "transfer" through some as yet unknown mechanism all this extra weight to the club during the impact interval in a way that doesn't result in an increase in clubhead speed. During the impact interval, being only 3/4 of an inch long, and lasting only 4/10,000 of a second, Hefty Harry will exert an extra 12.5 ft-lb of work compared to Tiny Tina. This will represent approximately 0.3% of the energy in the clubhead an instant before impact. Not significant, even if possible.

G2M
 
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Big discussion about this in the helping Hand Thread

How much weight added to the clubhead is needed to bend a shaft 1 inch down when hold still horizontally at the grip end?

How about 2 inches down? 3 inches?

The shaft loaded and sustained by Trovino or long hitters half-way down is even more than that. That's heavy!!! Real heavy!!!!!

Read the Helping Hand Thread from about page 10 to the end there was significant discussion about the role of this effect.

G2M
 
effective_mass_%203.gif


To make sure that everyone is on the same wavelength I have illustrated the situation with a simple figure.

Does a heavy golfer have the advantage of a larger effective clubhead mass, M+dm, relative to a very light person, when both arrive at impact with the same clubhead velocity?

Hence the question is not what you do or feel doing the downswing but rather if the larger body mass of a heavy golfer translates into a larger effective striking mass at impact compared to a tiny skinny golfer.

Biffer, with a PM, just made an excellent suggestion to link matters to an Iron Byron.

Indeed this way nobody can go astray about what one feels since as far as I know Iron Byron does not have any. ;)

Hence the question now becomes: Would a heavier Iron Byron hit it farther than a lighter one, when producing same clubhead velocity at impact?

I agree with g2m, both hit it the same. The previous thread on disconnected head mass comes into play here - the shaft is too flexible to play a role in the very short impact interaction at least if you believe the physicists that have looked at it (Cochran and Stobbs, Jorgensen, etc.) - which I'm inclined to do. Hitting out of long rough MIGHT be a different situation, but that's probably a different thread.
 
If you equalize actual clubhead mass and clubhead speed, then NO, and NO, (at least to any significant degree).

Let's suppose Hefty Harry outweighed Tiny Tina by 200 lbs, and that he was able to "transfer" through some as yet unknown mechanism all this extra weight to the club during the impact interval in a way that doesn't result in an increase in clubhead speed. During the impact interval, being only 3/4 of an inch long, and lasting only 4/10,000 of a second, Hefty Harry will exert an extra 12.5 ft-lb of work compared to Tiny Tina. This will represent approximately 0.3% of the energy in the clubhead an instant before impact. Not significant, even if possible.

G2M
g2m, I don't agree with your approach, and the numeric result, to show the effect of increasing somehow the mass of the clubhead with the body mass of a 200 lb golfer.

The proper way to see what would happen to the ball departure speed, U’, if all of the 100 kg (200 lb) could be added somehow to the clubhead mass, is simply to substitute it in:

U’ = [(1+e)* m1 / (m1+m2)]* V

Let e = 0.75, m2 = 46gr and V is 100 mph.

(1) m1 = 200gr, then U’ = 142 mph

(2) m1 = 200gr + 100 kg, then U’ = 175 mph

The extra 200 lb increases the ball departure speed significantly, 55.2 %.

Hence a very large difference indeed. To give an idea of magnitude below for 1% and 10% has been calculated.

To produce a 1% difference in ball departure speed only 11 gram is required to be added to the 200 gram of the clubhead.

To produce a 10% difference in ball departure speed 189 gram is required to be added to the 200 gram of the clubhead.
 
I don't agree.....

g2m, I don't agree with your approach, and the numeric result, to show the effect of increasing somehow the mass of the clubhead with the body mass of a 200 lb golfer.

The proper way to see what would happen to the ball departure speed, U’, if all of the 100 kg (200 lb) could be added somehow to the clubhead mass, is simply to substitute it in:

U’ = [(1+e)* m1 / (m1+m2)]* V

Let e = 0.75, m2 = 46gr and V is 100 mph.

(1) m1 = 200gr, then U’ = 142 mph

(2) m1 = 200gr + 100 kg, then U’ = 175 mph

The extra 200 lb increases the ball departure speed significantly, 55.2 %.

Hence a very large difference indeed. To give an idea of magnitude below for 1% and 10% has been calculated.

To produce a 1% difference in ball departure speed only 11 gram is required to be added to the 200 gram of the clubhead.

To produce a 10% difference in ball departure speed 189 gram is required to be added to the 200 gram of the clubhead.

There is a fundamental difference in our approach:

My calculation was based on the potential application of the heavy golfers weight not as a direct addition to the clubhead mass, which is what you have done. Note that my premise was that the clubhead speed and mass were constant between the two. Of course a heavier clubhead swung at the same speed will result in a higher ball speed.

My approach is to estimate what happens during only the impact interval as you requested. For your approach to be appropriate the golfer would have to literally transfer his extra mass and add it to the clubhead, in which case your calculation/approach would be correct, though not very plausible.

However, my supposition was that the heavy golfer could (somehow) transfer his extra weight into applied torque or force applied to the clubshaft, and to estimate the resulting "extra" work that would result from this weight transfer. This is the only way you could look at this since the only point of contact between the golfer and the club is at the grip. Whatever the golfer does has to be done there. If he is "transferring" weight into impact it has to go through the hands to the grip, shaft and clubhead in the form of torque applied at the grip. In my scenario, the ball speed would increase by about 8% or so. But, how conceivably could one do this without increasing clubhead speed? This is basically the same discussion we had in the other thread about a torque applied at the grip. (see your post #111) and change the 10 lb I suggested to the 200Lb we are now discussing.

To put it another way, If Goliath had use the same sling on David, would the rock have traveled faster? (Sorry Brian)

G2M
 
Swing radius?

Homer Kelley stated :-

"2-M-2. POWER REGULATION
Therefore, there are 15 variations available. Clubhead Lag Pressure Point pressure (6-C) is the Power Regulator . It meters out Power by sensing Clubhead Acceleration Rate and Direction. That is:

To vary the Effective Clubhead Mass, vary:
l. The Acceleration Rate (Lag Pressure 7-11)
2. The Swing Radius (length of Primary Lever Assembly
6-B-0)
To vary Clubhead Speed, vary:
1. Acceleration Time (Length of Stroke 10-21)
2. The Release Interval (Centrifugal Reaction 6-N-0)

So, it is optional to use any one, or any combination, of the four alternatives. (Also study 12-0 in this connection.)"


I think that this is a great thread - dissecting out the physics from the fables.

My intuitive thought is that Heavy Metal Iron Byron hits the same distance as the lightweight version ( assuming constant clubhead speed)...at least whilst golf balls are being used... maybe if cannon balls were used then ....

As for Homer's sugestion that swing radius is a means of increasing effective mass... clubhead energy has no way of "knowing" whether speed X is achieved on 3 foot or 6 foot radius...

Swing radius results in ideal impact alignmeents and forwad leaning shaft but can not increase the effective mass of the clubhead - or so it seems to me!

Await your thoughts...
 
Physics from Fables...

Homer Kelley stated :-

"2-M-2. POWER REGULATION
Therefore, there are 15 variations available. Clubhead Lag Pressure Point pressure (6-C) is the Power Regulator . It meters out Power by sensing Clubhead Acceleration Rate and Direction. That is:

To vary the Effective Clubhead Mass, vary:
l. The Acceleration Rate (Lag Pressure 7-11)
2. The Swing Radius (length of Primary Lever Assembly
6-B-0)
To vary Clubhead Speed, vary:
1. Acceleration Time (Length of Stroke 10-21)
2. The Release Interval (Centrifugal Reaction 6-N-0)

So, it is optional to use any one, or any combination, of the four alternatives. (Also study 12-0 in this connection.)"


I think that this is a great thread - dissecting out the physics from the fables.

My intuitive thought is that Heavy Metal Iron Byron hits the same distance as the lightweight version ( assuming constant clubhead speed)...at least whilst golf balls are being used... maybe if cannon balls were used then ....

As for Homer's sugestion that swing radius is a means of increasing effective mass... clubhead energy has no way of "knowing" whether speed X is achieved on 3 foot or 6 foot radius...

Swing radius results in ideal impact alignmeents and forwad leaning shaft but can not increase the effective mass of the clubhead - or so it seems to me!

Await your thoughts...

The Heavy Iron Byron will have the same gravitational mass before and after impact, as will the clubhead, same with the light IB. The only way to increase the momentum and kinetic energy of the clubhead is to increase the velocity of the object as Kelley notes above. An increase in velocity results in a higher clubhead speed, which violates the premise of the argument that clubhead speed remains constant. So, Heavy IB, and Light IB swinging the same clubhead at the same speed will have the momentum and kinetic energy at impact, and thus the same ball velocity. I think Kelley used the term "effective mass" because fewer people would understand momentum and kinetic energy. The only point of connection between the Iron Byron and the club is the "hands", and a "weight transfer" from the machine to the club could only be as a torque or force aplied at the grip, resulting in a higher velocity. That however violates the premise of equal clubhead speed.

G2M
 
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Homer Kelley stated :-

"2-M-2. POWER REGULATION
Therefore, there are 15 variations available. Clubhead Lag Pressure Point pressure (6-C) is the Power Regulator . It meters out Power by sensing Clubhead Acceleration Rate and Direction. That is:

To vary the Effective Clubhead Mass, vary:
l. The Acceleration Rate (Lag Pressure 7-11)
2. The Swing Radius (length of Primary Lever Assembly
6-B-0)
To vary Clubhead Speed, vary:
1. Acceleration Time (Length of Stroke 10-21)
2. The Release Interval (Centrifugal Reaction 6-N-0)

So, it is optional to use any one, or any combination, of the four alternatives. (Also study 12-0 in this connection.)"


I think that this is a great thread - dissecting out the physics from the fables.

My intuitive thought is that Heavy Metal Iron Byron hits the same distance as the lightweight version ( assuming constant clubhead speed)...at least whilst golf balls are being used... maybe if cannon balls were used then ....

As for Homer's sugestion that swing radius is a means of increasing effective mass... clubhead energy has no way of "knowing" whether speed X is achieved on 3 foot or 6 foot radius...

Swing radius results in ideal impact alignmeents and forwad leaning shaft but can not increase the effective mass of the clubhead - or so it seems to me!

Await your thoughts...
Golfbulldog, up till Monday I can’t spent much time posting on this forum. Thanks for posting HK’s 2-M-2.

Hopefully the real experts on HK will come forward to help us understand what HK meant exactly by ‘effective mass’. ;)
 
New theory?


People often confuse inertial mass (IM) with gravitational mass(GM). GM is what you get when you put an object on a scale. IM is an objects resistance to acceleration. Wikipedia has a good explanation at http://en.wikipedia.org/wiki/Mass

The Heavy Iron Byron will have the same gravitational mass before and after impact, as will the clubhead, same with the light IB. The only way to increase the IM of the clubhead is to increase the accelaration of the object as Kelley notes above. An increase in acceleration results in a higher clubhead velocity, which violates the premise of the argument that clubhead speed remains constant. So, Heavy IB, and Light IB swinging the same clubhead at the same speed will have the Inertial Mass at impact, and thus the same ball velocity. I think Kelley use the term "effective mass" because fewer people would understand inertia.

G2M
golf2much is above part of a new theory you have developed, to be published soon? :D

You indicate that inertial mass increases when subjected to acceleration?

What about the Galilean and Einstein equivalence principles?

Gravitational mass can hence change also?

What about conservation of mass?

Am rather curious. ;)
 
Needed a little controversy in the thread

golf2much is above part of a new theory you have developed, to be published soon? :D

You indicate that inertial mass increases when subjected to acceleration?

What about the Galilean and Einstein equivalence principles?

Gravitational mass can hence change also?

What about conservation of mass?

Am rather curious. ;)

No new theory, just sticky fingers. Should have read inertia, not IM. Got to keep you on your toes somehow. Above post edited to correct.

G2M
 
Yet another new theory?

People often confuse inertial mass (IM) with gravitational mass(GM). GM is what you get when you put an object on a scale. IM is an objects resistance to acceleration. Wikipedia has a good explanation at http://en.wikipedia.org/wiki/Mass

The Heavy Iron Byron will have the same gravitational mass before and after impact, as will the clubhead, same with the light IB. The only way to increase the Inertia of the clubhead is to increase the accelaration of the object as Kelley notes above. An increase in acceleration results in a higher clubhead velocity, which violates the premise of the argument that clubhead speed remains constant. So, Heavy IB, and Light IB swinging the same clubhead at the same speed will have the Inertia at impact, and thus the same ball velocity. I think Kelley use the term "effective mass" because fewer people would understand inertia.

G2M
inertia_mass.gif

golf2much,
Inertia is that quantity which is solely dependent upon mass.
The mass of a body does not change with acceleration, hence
The inertia of a body does not change with acceleration either.
Only a change in mass can change the inertia, not acceleration. :D
 
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