# Kinetic energy and size of the golfer versus club speed??



## Jeffress77 (May 4, 2011)

An acquaintance of mine and I were having a discussion about driving distances.

As an avid archer, I am also familiar with kinetic energy differences between mass weight, speed and kinetic energy supplied from a projectile (in our case a golf ball).

Here is our argument:

One golfer large and very strong
One golfer small and weaker
Club speed exactly the same

I argue that the larger, stronger golfer will still hit the ball farther than the smaller golfer.

I would say that it is evident that a more burly, heavy golfer would not be able to generate the sheer club speed that a smaller golfer would generate. I was thinking the strength and energy loaded behind the club of the larger man at a slower speed would drive the ball farther than a weaker man, simply swinging the club slightly faster than the larger man, but not generating the same force or momentum behind the ball on the follow through.

Like in baseball, the skinny flexible batters should be able to swing the bat much faster than the burly designated hitters, but the energy loaded upon the impact is much greater with the stronger batters, creating a longer drive distance.

Am I completely wrong here? If the golfers are using the same equipment, and the big strong golfer swings at 90mph (let's just say) and the skinny guys swings at 100mph, wouldn't the bigger golfer's energy be equal or greater that of the smaller one?

Hopefully I get some good answers, because I haven't found many haha!

Thanks for reading such a complex first post!

-NW Indiana golfer


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## keiko (Apr 19, 2011)

There are so many variables that it is impossible to just make that simple statement you are making. When I have more time, I will post the variables, short on time now.
Suffice it to say, not that simple.



Jeffress77 said:


> An acquaintance of mine and I were having a discussion about driving distances.
> 
> As an avid archer, I am also familiar with kinetic energy differences between mass weight, speed and kinetic energy supplied from a projectile (in our case a golf ball).
> 
> ...


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## Big Hobbit (Nov 2, 2010)

Crikey, that's a tough one to answer. I've got to dust off some really old brain cells for this one. No doubt someone will be along shortly to correct me.

To use a bit of an analogy. Lets assume you want to drive a big nail into a plank. You start off with a small hammer and hit it as hard as you can. The nail might go in a few millimetres, or tenths of an inch. You then get a sledge hammer and hit the nail once, applying the same power, and the nail goes in in one hit. So what has changed? 1) The 'mass' of the hammer, and 2) the length of the handle.

In golfing terms if the same power is applied by a small golfer and a big golfer the big golfer will hit the ball further. Why? The length from the fulcrum, i.e. the shoulders, to the clubhead. Force = mass x distance. If the distance is greater then the resulting force will be greater. Its a leverage thing.

So if the big guy swings at 90mph, with an arm length X the ball would travel, say, 300yds.
So if the small guys swings at 100mph but with an arm length of X minus 2 inches the ball would also travel 300yds.

Sorry if I haven't explained it very well, or vaguely, but it nearly 40 years since I was taught physics.


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## stevel1017 (Apr 30, 2007)

if they are swinging identical clubs at identical speeds, generating the same launch angel and spin,
the balls will go the same distance. The golfer is not applying the force to the ball, rather the clubhead is. The golfer is merely the engine, like Iron Byron
In Hobbits example, the mass has changed, but if we leave the hammer the same, and change a big guy and small guy, if they both use the same force the nail will go the same distance

Key Factors of Golf Ball Distance

The distance a golf ball will travel is determined by:

initial velocity which is the initial speed of the ball 
initial angle of flight, which is the angle at which it is hit into the air 
Spin that has been imparted on the ball by the club 
These three factors are significantly affected by a number of other external factors, such as the percentage of full contact hits, golf clubhead speed, and swing path. The interrelationship of these external factors greatly influence the distance that a golf ball will carry upon impact

it is the ball speed, spin and launch angle that determine the distance
the club is just the device to set the ball on the launch angle, with the spin and speed


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## Big Hobbit (Nov 2, 2010)

Steve, you're right, if the clubhead speed is the same for the small guy as it is for the big guy then the ball will travel the same distance.

But if the the force(power) from the point of the fulcrum, the shoulders, is the same the big guy will hit it further - the leverage thing. The longer the lever, i.e. from the shoulder to the end of the crowbar, the more power is generated. So in that respect, the little guy has to apply more power, because of the smaller leverage, to generate the same distance.

Or at least I think so...


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## stevel1017 (Apr 30, 2007)

yes Hobbit, the little guy does have to apply more force to generate the same clubhead speed
I am a little guy (5 foot 5), and was playing with this guy 6 foot 2, and kept driving it by him by 20 yards, he said to me, imagine if you were my size how far you could hit the ball.
But if I were bigger, my technique and timing may not be the same


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## keiko (Apr 19, 2011)

Clubhead speed, strength and flexibility play important parts of getting distance but there is so much more such as technique, coordination, angle of impact, spin rate from the swing, dynamic weight transfer etc. Entire volumes have been written.
Some equations that apply are: T=FXL or Torque equals force times leverage; F=MA or Force equals mass times acceleration; and, D=MA or distance equals Mass times Acceleration.
Other factors are the magnus effect and smash factor as well as COAM(coefficient of angular momentum/which applies to impact position.
Also, the optimal place on the clubhead is not dead center but rather just slightly above dead center.
Since I don't know about any of you, I will use myself as an example. I use a 48" shaft on my driver with a 7 degree head and I am only 5'9" but I can hit the ball over 300 yards on at least 4 occasions per round and I am not swinging hard to do it. Why?
On those occasions, I have maximized the smash factor at impact so the ball flies a long way but my equipment allows me to get lots of roll also. For my swing, if I used a 10 degree driver for example, I could or would not get that distance. So while alot of factors play into getting distance, equipment can't be ignored.
K.I.S.S.


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## Tim (Jan 8, 2011)

How do you measure club shaft length?


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## keiko (Apr 19, 2011)

There are two ways: The USGA measures one way and max allowed is 48" which is what I have because it meets USGA rules and I can play in tournaments without a problem.
The LDA measures another way and their max is 50" which converts to 48" when using the USGA method.
One method has the club straight up and the other has the club at an angle.
Google it.




Tim said:


> How do you measure club shaft length?


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## Tim (Jan 8, 2011)

This is interesting. All my other clubs are equal in length or even a bit longer than other clubs I compare them to. Except my driver. It is shorter. I did look it up, and I had measured it correctly. Its 43 1/2 in. long. I have heard somewhere the standard length for a driver is 45" and according to online fitting guides I should have 1" over. So a 46" club. thats about how long the Diablo Octane I demoed for 9 last weekend was. The length was more comfortable, but I still had accuracy problems. I was wondering if I might need a stiffer shaft.
I was thinking of going down to Golfsmiths in a couple weeks and getting fitted and go from there.


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## keiko (Apr 19, 2011)

keep in mind golfsmith fitters are just guys off the street; if you could find someone who just does fitting/teaching, it would result in a more professional fitting.
Like most, I believed the hype about 43" drivers, ie. tiger uses a 43.5", all the tour pro's use 44" etc. that stuff doesn't apply to most of us.
I have used 50" Long Drive clubs and I get another 20 yards at least but accuracy suffers. I settled for a 48" XS shaft and just worked on perfecting my swing. My swing speed has improved from 108 to over 120 due to my conditioning and swing coach etc, so I could use XX or XXX if I wanted to but I like the softer crushing feel on center hits.
Work on your swing and fundamentals and you can use anything you want but get your swing speed checked-not just one swing but get at least 20 swings at 75% effort then take an average.
Center face hits is what you want and that takes a little practice.
I do not want to brag but at 66, I am just crushing the ball and average over 280 with a few drives over 300 yards per round.
My gir are in 80+%, and I average 28-30 putts per round.



Tim said:


> This is interesting. All my other clubs are equal in length or even a bit longer than other clubs I compare them to. Except my driver. It is shorter. I did look it up, and I had measured it correctly. Its 43 1/2 in. long. I have heard somewhere the standard length for a driver is 45" and according to online fitting guides I should have 1" over. So a 46" club. thats about how long the Diablo Octane I demoed for 9 last weekend was. The length was more comfortable, but I still had accuracy problems. I was wondering if I might need a stiffer shaft.
> I was thinking of going down to Golfsmiths in a couple weeks and getting fitted and go from there.


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