Speed vs Force, With Respect to Distance

[nevets88]

Not sure I understand the difference between speed and force here. Practically speaking, you have both huge guys and skinny guys who hit it a long way.

Segment speed or segment force, which one is of more value in golf?

Quote

Historically in golf segmental speed (angular velocity) has been the accepted measurement of how the body segments (pelvis, ribcage, arm, hand and club) produce and apply speed and this has often been seen by some as the predictor of/correlation to driving distance/ball displacement. However we are now able to provide segment force values through the new information produced by the Bull3D software. This has revealed some fascinating and intriguing patterns and discoveries, one being that when it comes to its influence on driving distance and club head speed, what is of more value, segment speed or segment force? 

...

In this very short reflection, below are the speed and force values of these two players, plus the force application plots, you will see how the player who was self-described as a short hitter produces significantly more peak segment speed than the long drive champion, but substantially lower peak forces. Also, in the force application plots, asides from the club the player with high speeds fails to apply the peak segment force with any segment on impact whereas the long drive champion achieves peak force with all segments on impact, with the slight exception of the thorax which happens just after impact.

http://www.bull3d.net/download/Article-SegmentSpeedVsSegmentForce.pdf

[SavvySwede]

Looks like a bunch of BS to me. 

[freshmanUTA]

1 hour ago, nevets88 said:

Not sure I understand the difference between speed and force here. Practically speaking, you have both huge guys and skinny guys who hit it a long way.

Segment speed or segment force, which one is of more value in golf?

http://www.bull3d.net/download/Article-SegmentSpeedVsSegmentForce.pdf

Simply stated the difference is: 

Speed=Time/Distance

Force=Mass * Accelleration(The article has it wrong)

 

It gets a little more complex when you add in angular velocity and such but the simplest way, and the way they are trying to explain it is along the lines of:

 

Long drivers have a fast club-head speed due to a shorter acceleration into the ball, which according to the defenition of Force, would mean they have greater force.

 

Their test "Short-Driver" swung fast but couldn't have the mass of his body match up with a fast Accelleration into the ball which means he provides less force which makes the ball go shorter.

 

 

For example.(It's an EXTREME exaggeration of time, weight, and pretty much everything.)

Both players swing at 100MPH with a club that has a mass of 100 grams..

Player A accelerates at 10MPH/S

Player B accelerates at 5MPH/S

 

Player A would swing at 100 MPH with 1000N of Force.

 

Player B would swing at 100 mph with 500N of force.

 

Now, knowing how a golf swing works, these numbers are severely skewed and Player B would have a down-swing that took nearly 5 seconds to complete.

 

In reality the differences in acceleration are very small but can cause some changes in distance. But the calculations are way more advanced when you bring factors such as angular velocity into play. 

 

IMO the writer of that post is someone who desperately wants to make groundbreaking research but oversimplified the research and calculations he was doing.

Edited February 23, 2016 by freshmanUTA
Added parentheses

[GolfLug]

21 minutes ago, SavvySwede said:

Looks like a bunch of BS to me. 

Yeah, bull in 3D, no less..:-)

15 minutes ago, freshmanUTA said:

Simply stated the difference is: 

Speed=Time/Distance

Force=Mass * Accelleration(The article has it wrong)

 

It gets a little more complex when you add in angular velocity and such but the simplest way, and the way they are trying to explain it is along the lines of:

 

Long drivers have a fast club-head speed due to a shorter acceleration into the ball, which according to the defenition of Force, would mean they have greater force.

 

Their test "Short-Driver" swung fast but couldn't have the mass of his body match up with a fast Accelleration into the ball which means he provides less force which makes the ball go shorter.

 

 

For example.(It's an EXTREME exaggeration of time, weight, and pretty much everything.)

Both players swing at 100MPH with a club that has a mass of 100 grams..

Player A accelerates at 10MPH/S

Player B accelerates at 5MPH/S

 

Player A would swing at 100 MPH with 1000N of Force.

 

Player B would swing at 100 mph with 500N of force.

 

Now, knowing how a golf swing works, these numbers are severely skewed and Player B would have a down-swing that took nearly 5 seconds to complete.

 

In reality the differences in acceleration are very small but can cause some changes in distance. But the calculations are way more advanced when you bring factors such as angular velocity into play. 

 

IMO the writer of that post is someone who desperately wants to make groundbreaking research but oversimplified the research and calculations he was doing.

Good post man. Yes, speed without proper direction (velocity) does not translate to applied force. Some numbers are just outright suspect, specifically arm speed. Says, short hitter's arms are appx 30% faster. Don't get that at all.   

[SavvySwede]

26 minutes ago, freshmanUTA said:

Simply stated the difference is:

Speed=Time/Distance

Force=Mass * Accelleration(The article has it wrong)

It gets a little more complex when you add in angular velocity and such but the simplest way, and the way they are trying to explain it is along the lines of:

Long drivers have a fast club-head speed due to a shorter acceleration into the ball, which according to the defenition of Force, would mean they have greater force.

Their test "Short-Driver" swung fast but couldn't have the mass of his body match up with a fast Accelleration into the ball which means he provides less force which makes the ball go shorter.

For example.(It's an EXTREME exaggeration of time, weight, and pretty much everything.)

Both players swing at 100MPH with a club that has a mass of 100 grams..

Player A accelerates at 10MPH/S

Player B accelerates at 5MPH/S

Player A would swing at 100 MPH with 1000N of Force.

Player B would swing at 100 mph with 500N of force.

Now, knowing how a golf swing works, these numbers are severely skewed and Player B would have a down-swing that took nearly 5 seconds to complete.

In reality the differences in acceleration are very small but can cause some changes in distance. But the calculations are way more advanced when you bring factors such as angular velocity into play. 

IMO the writer of that post is someone who desperately wants to make groundbreaking research but oversimplified the research and calculations he was doing.

That's not what is going on. You can't get your body weight into the shot. 100mph of clubhead speed will produce a max ball speed of around 150mph no matter the size of the player or how they accelerated to get to that speed at impact. In the paper they are comparing a long drive guy swinging 140 to some regular bloke swinging much slower. It's apples and oranges. Comparing degrees of rotation/second is almost useless if you figure the long drive guy likely has a swing arc several feet longer over which to bring his clubhead up to speed, the long drive guy most likely has a better swing to boot(they don't even mention the skill level of the other golfer.)

 

6 minutes ago, GolfLug said:

Yeah, bull in 3D, no less..:-)

Good post man. Yes, speed without proper direction (velocity) does not translate to applied force. Some numbers are just outright suspect, specifically arm speed. Says, short hitter's arms are appx 30% faster. Don't get that at all.   

They're measuring arm rotation though, that just means he rolls his arms over like a high handicapper.

[freshmanUTA]

15 minutes ago, SavvySwede said:

That's not what is going on. You can't get your body weight into the shot. 100mph of clubhead speed will produce a max ball speed of around 150mph no matter the size of the player or how they accelerated to get to that speed at impact. In the paper they are comparing a long drive guy swinging 140 to some regular bloke swinging much slower. It's apples and oranges. Comparing degrees of rotation/second is almost useless if you figure the long drive guy likely has a swing arc several feet longer over which to bring his clubhead up to speed, the long drive guy most likely has a better swing to boot(they don't even mention the skill level of the other golfer.)

 

They're measuring arm rotation though, that just means he rolls his arms over like a high handicapper.

I understand you can't get your body weight into the shot, it's not like hockey. That's why the mass figure I used was an example club. Regardless, I was attempting to explain how the article thinks it works.

 

I read through it and confused what he said about faster segment speeds with what I assumed was swinging faster than the long driver with less controlled mass. 

 

 

The whole article is misinformative, and I discredited it as soon as I saw him put: Force = Mass / Accelleration.

 

[SavvySwede]

6 minutes ago, freshmanUTA said:

I understand you can't get your body weight into the shot, it's not like hockey. That's why the mass figure I used was an example club. Regardless, I was attempting to explain how the article thinks it works.

I read through it and confused what he said about faster segment speeds with what I assumed was swinging faster than the long driver with less controlled mass. 

The whole article is misinformative, and I discredited it as soon as I saw him put: Force = Mass / Accelleration.

 

I imagine the same physics apply to hockey as well. No reason why they shouldn't.

Sidenote:(You don't need to space your paragraphs/lines so far apart, makes it strange to read)

[Tee2Trees]

Obviously force creates speed, so they are one in the same.

However, the stronger player (which I am not) should be able to create the same speed with a heavier clubhead.  This extra mass creates forgiveness through better energy transfer on off-center hits (regardless of the club's "MOI").  So in this roundabout way, the stronger player -- equipped with a heavier clubhead -- creates more ball speed for a given swing speed.

I'm still waiting for some OEM marketing department to properly explain the benefit of short and heavy, but I have yet to see it happen.  Wishon pushes the 44" driver length, but emphasizes the center-contact benefit while neglecting the head weight benefit.

[DaveP043]

I didn't realize this at first, but this is simply a sales pitch, a reason for someone to buy or use the Bull3D system of swing analysis.  No doubt there's good information that their system can provide, and some of the other articles available on their website seem fairly interesting, but the force v. angular velocity v. velocity stuff seems like hocus-pocus to me.  I'm particularly confused by the "force" calculations.  Force is exerted by something on another something.  What exactly IS pelvis force, and what is the pelvis acting on?  Or perhaps the pelvis is applying not "force", but rather "torque"  to some other part of the body. I think its all rather misleading, but if you buy the Bull3D services, I'm sure they'll explain it all to you.  For a fee. 

[Lihu]

46 minutes ago, Tee2Trees said:

Obviously force creates speed, so they are one in the same.

However, the stronger player (which I am not) should be able to create the same speed with a heavier clubhead.  This extra mass creates forgiveness through better energy transfer on off-center hits (regardless of the club's "MOI").  So in this roundabout way, the stronger player -- equipped with a heavier clubhead -- creates more ball speed for a given swing speed.

I'm still waiting for some OEM marketing department to properly explain the benefit of short and heavy, but I have yet to see it happen.  Wishon pushes the 44" driver length, but emphasizes the center-contact benefit while neglecting the head weight benefit.

Yeah, that's pretty much true. However, the stronger player needs much more core strength to move his bigger arms as fast as someone with lighter arms. There is a diminishing return as they are both only hitting a 65gm ball. http://www.tutelman.com/golf/swing/golfSwingPhysics4.php

http://zonalandeducation.com/mstm/physics/mechanics/momentum/introductoryProblems/momentumSummary2.html

Increasing the mass/Force/dwell time will all increase the velocity roughly proportionally.

Attached the integral form.

Impulse Mom Eqn Particles 1.pdf

[SavvySwede]

33 minutes ago, Tee2Trees said:

Obviously force creates speed, so they are one in the same.

However, the stronger player (which I am not) should be able to create the same speed with a heavier clubhead.  This extra mass creates forgiveness through better energy transfer on off-center hits (regardless of the club's "MOI").  So in this roundabout way, the stronger player -- equipped with a heavier clubhead -- creates more ball speed for a given swing speed.

I'm still waiting for some OEM marketing department to properly explain the benefit of short and heavy, but I have yet to see it happen.  Wishon pushes the 44" driver length, but emphasizes the center-contact benefit while neglecting the head weight benefit.

Clubhead speed is a much larger factor than mass so the benefit of any extra mass is always offset by the loss in speed.  So though you could theorically increase the smash factor by a tiny fraction by adding weight, the player won't increase their max ball speed or distance.

So Wishon is correct, the only benefit of short and heavy is for the player to have a better sense of the club and make consistently better contact.

[Lihu]

1 minute ago, SavvySwede said:

Clubhead speed is a much larger factor than mass so the benefit of any extra mass is always offset by the loss in speed.  So though you could theorically increase the smash factor by a tiny fraction by adding weight, the player won't increase their max ball speed or distance.

So Wishon is correct, the only benefit of short and heavy is for the player to have a better sense of the club and make consistently better contact.

This is true. http://www.tutelman.com/golf/swing/golfSwingPhysics4.php

[GolfLug]

1 hour ago, SavvySwede said:

They're measuring arm rotation though, that just means he rolls his arms over like a high handicapper.

Yes, but he mentions hand rotation as a separate metric also. So in effect I assumed arm rotation he meant this to how fast arms are being whipped through in an arc. But yes, if it is only rotation of forearm in itself then it is seems to have no bearing on how much clubhead speed is being generated.

Overall this whole is starting to sound like a grossly negligent and or misleading use of physics to what @DaveP043  is referring to just a poorly developed sales pitch.

1 hour ago, SavvySwede said:

That's not what is going on. You can't get your body weight into the shot. 100mph of clubhead speed will produce a max ball speed of around 150mph no matter the size of the player or how they accelerated to get to that speed at impact. In the paper they are comparing a long drive guy swinging 140 to some regular bloke swinging much slower. It's apples and oranges. Comparing degrees of rotation/second is almost useless if you figure the long drive guy likely has a swing arc several feet longer over which to bring his clubhead up to speed, the long drive guy most likely has a better swing to boot(they don't even mention the skill level of the other golfer.)

 

 

Yes, not what's going on in a golf swing. I think @freshmanUTA simply trying to decipher his basic use of physics however misapplied, which I think we all agree on so far.

 

Yupp, 3DBull($**t).

[Lihu]

1 hour ago, freshmanUTA said:

The whole article is misinformative, and I discredited it as soon as I saw him put: Force = Mass / Accelleration.

Now that's funny!

 

[freshmanUTA]

1 hour ago, SavvySwede said:

I imagine the same physics apply to hockey as well. No reason why they shouldn't.

Sidenote:(You don't need to space your paragraphs/lines so far apart, makes it strange to read)

I'm not sure why they do that, I only press enter once..

In hockey you use your body weight to flex a stick which provides all the power. It's the only sport I can really think of where the use of your weight dictates how hard the shot is.

5 minutes ago, Lihu said:

Now that's funny!

 

Amateur Hour.

[billchao]

I looked at it briefly, but the thing that stands out to me is the long drive champ hits his peaks pretty much at impact, whereas the short hitter is all over the place.

If anything I would say that the long driver generates more force because he's using his body more efficiently. I wonder if the short hitter can turn his hips and torso faster simply because he's firing one and then the other, as opposed to being more in sync?

It looks like a flawed experiment to me, as if the author had a conclusion he wanted to prove and didn't really look at everything.

[DaveP043]

I took a look back at what their system actually measures.  They measure the locations of a number of points on the body and the golf club through a golf swing, as well as using force plates to measure stresses at the ground level.  Everything else is calculated.  Motions, including velocity and acceleration and their angular counterparts, are pretty straighforward.  Anything involving force, torque, or moment has to rely on some significant assumptions about mass and its distribution throughout the body.  Whenever people start making those kinds of assumptions (I more often call these guesses), and then basing their definitive conclusions on the results of the calculations, I generally walk the other way.  GIGO, Garbage in, garbage out.  I have no doubt that the motions studies can have value, but the rest is just guesswork.  I know lots of people (including many engineers I deal with) who think that if a computer prints it out, that its good.  I know better.

Oh, they also say somewhere that speed is time over distance, not the other way around.

[SavvySwede]

8 minutes ago, freshmanUTA said:

In hockey you use your body weight to flex a stick which provides all the power. It's the only sport I can really think of where the use of your weight dictates how hard the shot is.

Well I don't know anything about hockey so I assumed you just hit the puck. Just read about the slapshot on Wikipedia and it said they intentionally hit the ground first to bend the stick, interesting stuff. Learn something new everyday.

3 minutes ago, billchao said:

I looked at it briefly, but the thing that stands out to me is the long drive champ hits his peaks pretty much at impact, whereas the short hitter is all over the place.

If anything I would say that the long driver generates more force because he's using his body more efficiently. I wonder if the short hitter can turn his hips and torso faster simply because he's firing one and then the other, as opposed to being more in sync?

It looks like a flawed experiment to me, as if the author had a conclusion he wanted to prove and didn't really look at everything.

Yeah they don't actually mention the "short hitter's" skill level. A huge omission on their part. They should have grabbed a scratch golfer at the very least.