It's a Real Force, this Centrifugal Thing.

[mandrin]

The simplified version is this, Centrifugal Force is a fictitious force, but what we call the force other wise know as Centrifugal Force, is created as much from the GOLFER pulling UP THE GRIP on the club as anything else.

Brian,

I don't agree. Centrifugal force is not fictitious. In a golf swing it is as real as you and I existing.

I can't blame you for your definition of centrifugal force as it is common to find it mentioned this way in many official science textbooks. It is frequently defined as the inertial tendency for rotating particles to continue to move away from the axis of rotation. Yet such a type of definition is in flagrant contradiction with Newton's third law.

Another argument frequently used to deny the existence of centrifugal force is invoking rotating non inertial reference frames.....vehicles going through corners and people sliding on seats or objects sliding around on dashboards. Nice, interesting, but just not appropriate. Golf is simply not played inside vehicles. Golf is played with both feet on the surface of mother earth and hence in a nice inertial Newtonian reference frame.

There is another possible source of confusion as the term centrifugal force is also sometimes used in the Lagrangian formulation of Newtonian Mechanics but we can safely ignore this one. There is indeed a very peculiar and continuous confusion attached to centrifugal force. Some scientists even get very emotional and almost fanatic about it as was shown convincingly by a former poster, nmgolfer.

I think a lot has to do with the fact that we don't really have an understanding of what exactly is inertia or an inertial force. This has been so from the very beginning, and continued so for many hundreds of years to pose a problem for scientists and it still is. Also scientists seems to have an aversion for anything which is a reaction force, they prefer action and cause and inclined to ignore what comes as a result. Also reaction forces frequently don't show up in mathematical formulations, hence rather natural to start ignoring them.

A good starting point for discussion is that we can safely assume that not a single scientist on earth will dispute Newton for normal everyday mechanics. Hence let's not invoke relativity, quantum mechanics, and the like.

-1- Hence we assume that Newton's third law is accepted by all scientists.

-2- We also assume that all scientists accept that what can be measured does exist.

With these two points in mind visit a post I have done a while ago on this subject and see if you agree with my arguments.

It is interesting to google with the words centrifugal and centripetal and one will find that engineers readily use 'centrifugal' but rarely 'centripetal' to specify many items/processes such as centrifugal pump, centrifugal blower, centrifugal clutch, centrifugal stiffening etc. Not bad for something which seemingly does not exists. It is also quite funny to read a scientific text and have the author mentioning that centrifugal force not really exists but then immediately continues saying that it is so convenient to use it that he will just do as if it existed from there on.

 

[ZAP]

I am having trouble with this argument in terms of who is saying what.
I think Brian is saying centripetal force is not what releases the club and he is not saying it does not exist at all. Only that it is not the primary or even significant force which does the releasing. There has to be some force out from the center because if you let go of the club it flies away from you.

My point is it seems like there are two discussion going on from my point of view.

OK how far off am I?

 

[mandrin]

I am having trouble with this argument in terms of who is saying what.
I think Brian is saying centripetal force is not what releases the club and he is not saying it does not exist at all. Only that it is not the primary or even significant force which does the releasing. There has to be some force out from the center because if you let go of the club it flies away from you.

My point is it seems like there are two discussion going on from my point of view.

OK how far off am I?

Eyeoffish,

Sorry. I think you're way off base.

-1- My point is concerning centrifugal force not centripetal force.
-2- Also not about release of the club but solely if centrifugal force is real or not.
-3- Fictitious: unreal - lacking in reality or substance or genuineness.

 

[Brian Manzella]

Mandrin.

I was saying that Zick said that the FORCE WE CALL CENTRIFUGAL—the outward pull feeling of the clubhead—is as much caused by the golfer PULING UPWARD ON THE GRIP as any body rotation.

 

[mandrin]

I was saying that Zick said that the FORCE WE CALL CENTRIFUGAL—the outward pull feeling of the clubhead—is as much caused by the golfer PULING UPWARD ON THE GRIP as any body rotation.

Brian,

It is not very clear what you state, moreover you conveniently left out, 'Centrifugal Force is a fictitious force'.

But I fully realize that for a layman it is very confusing to understand. Wherever he looks, even in serious science textbooks or publications, centrifugal force is frequently mentioned as being fictitious.

Eventually I will try to clear up this confusion existing for too long already. Since it is against mainstream thinking and contrary to well entrenched concepts I will take the time it takes to do a proper job.

For the moment let me just say that...

-1- centrifugal force does exist as a real force in a golf swing, yet,

-2- its action in golf is completely different from the one, universally accepted.

 

[dannyc]

For the moment let me just say that...

-1- centrifugal force does exist as a real force in a golf swing, yet,

-2- its action in golf is completely different from the one, universally accepted.

nice cliffhanger

 

[savydan]

Is Dr. Zick a doctor of Physics or Chemcial Engineering? Not that it really matters. Chem E's are smart dudes.

 

[Brian Manzella]

Is Dr. Zick a doctor of Physics or Chemcial Engineering?

Ph.D.(1983), Chemical Engineering, Stanford University.

 

[Brian Manzella]

One more time...

Dr. Zick says that "Centrifugal Force" is caused more by the GOLFER applying a torque in the direction of "pulling the grip off of the club," than by the pivot's internal rotation.

Can we talk about that, because that's pretty important.

BTW, I believe in Centrifugal Force.

 

[JThompson]

Centrifigal force is the force pulling away from the center of a rotation. It does exist on a golf swing. What creates this force in the golf swing can be debated. The fact that it exists cannot be debated.

Centripital force is the force pulling toward the center of a rotation. This force also exists. It is the reason the club doesn't fly out of a golfers hand during the swing. Just like how the force of tires on the road doesn't allow a car to swing off the road on a turn. It too exists in every swing.

 

[ej20]

The Higgs Boson when found will end all arguments......

 

[spktho]

Dr. Zick says that "Centrifugal Force" is caused more by the GOLFER applying a torque in the direction of "pulling the grip off of the club," than by the pivot's internal rotation.

Can we talk about that, because that's pretty important.

Caused by the increase in velocity of the arms/hands compared to the relatively slow body pivot?

 

[ej20]

Centrifugal and centripetal force are one and the same depending on your point of reference.To an outside observer of the swing the force is centripetal(center seeking).If you were inside the clubhead and had instruments to measure the force it would be centrifugal(center fleeing).It's as simple as that.

 

[Brian Manzella]

Centrifugal and centripetal force are one and the same depending on your point of reference.To an outside observer of the swing the force is centripetal(center seeking).If you were inside the clubhead and had instruments to measure the force it would be centrifugal(center fleeing).It's as simple as that.

I have to check again with Dr. Zick, but I am pretty sure it is NOT that easy.

 

[Shot Limit]

Centripital force is the force pulling toward the center of a rotation. This force also exists. It is the reason the club doesn't fly out of a golfers hand during the swing. Just like the force of tires on the road doesn't allow a car to swing off the road on a turn. It too exists in every swing.

I'm not sure what car tires have to do with this. Isn't friction what keeps the car from swinging off the road, the same way the pressure on the grip of the club keep the club from flying from the hands? What happens on icy roads?

 

[ej20]

I have to check again with Dr. Zick, but I am pretty sure it is NOT that easy.

Probably not but like the golf swing one can make it simple or complicated.

I would just like to know from the player swinging the club point of reference which is the better force to focus on.I don't really care about the theory,I'll leave that up to the Einsteins of this world.

 

[Steve Greffen]

Actually it is a "Brian Manzella Golf Forum" not some open golf forum that has no direction or leadership. You can agree or disagree that physics is focused on but to give an answer to a question on force and then say whatever I just want a simple answer for a golfer perspective is a little having it both ways.

Certainly not all the content on this forum is meant for the golfer's only perspective and therefore the golfer only needs to filter what they want and don't. Instuctors and researchers alike tune in and find this content valuable.

Steve

 

[Mike O]

Forces

I'm really afraid to enter this thread! Especially since I don't have a physics background - only some basic logic skills.

However, this topic seems to come up again and again - and no matter how smart Mandrin or others are- it appears to me that no one is clearly clarifying or communicating the concepts at hand. It seems to me Mandrin - that using Newton's third law to verify or prove centrifugal force/ centripetal force - is going down the wrong path! The path to confusion - at least from my current perspective.

For me it's much simpler to understand the nature of the term- by looking at Newton's first law "There is no change in the motion of a body unless a resultant force is actin upon it." 1) Forces are vectors - "straight lines".
2) In order to create a rotary motion -it takes at least two vectors i.e. one to get something moving in a straight line and then one to pull it off the straight line - and then repeat that over and over - and you create a rotary motion.
3) The whirling thing- rock on the end of a string or the clubhead on the end of a shaft- wants to move in a straight line- and you need to keep "pulling it off" that straight line to create rotary motion.

There's a moving clubhead that wants to move straight and there is some force - in this case assuming that you are the golfer- pulling it towards yourself - so that you can re-direct the straight line flight of the clubhead.

Here is where Mandrin could probably answer this question for me- on a strictly physics approach - Would the force that continually pulls the clubhead off it's straight line effort- actually be directly exactly at the center of the circle? Or would it be "off center". The reason I ask this is that when we are commonly talking about centripetal or centrifugal forces- I think that what people are imagining or thinking of are forces that go directly inward along the string and are going directly outward along the string if you are whirling a rock. That's where the whole Newton's third laws lead us to thinking. That's not the context that I see Centrifugal force.

Let's just look at the term "centrifugal force" - the "outward" force - in my example above with the two force vectors. It's the clubhead wanting to move in a straight line - 90 degrees from the string line - at a tangent from the circle. That's the center fleeing force. It certainly wants to move away from the center- but not directly along the shaft or string. So I would call that force vector - centrifugal- center fleeing. And I would call the other force vector- centripetal- whether it moves directly towards the center or not.

Hopefully- one can understand my two vector creating rotary motion concept of centrifugal force- it actually ties in with Homer Kelley's understanding of the concept. He defined it from a Mechanical perspective in the Glossary of his book as "The resistance of the Inertia in an orbiting object to change in direction".

If you post to my response here - what would I like to see?
1) An understanding of what I said and the context that I wrote it.
2) If you feel I am correct in some context - please let me know
3) If you think a different context is more appropriate or I made a mistake- please try to state it clearly or stay on one particular item in my post initially - so that I can learn from your post. I'm a fan of learning - that means I have no problem with disagreements however I'm not a fan of Mockery, and condescending comments - while they might be fun-doesn't really float my boat.

 

[ej20]

Actually it is a "Brian Manzella Golf Forum" not some open golf forum that has no direction or leadership. You can agree or disagree that physics is focused on but to give an answer to a question on force and then say whatever I just want a simple answer for a golfer perspective is a little having it both ways.

Certainly not all the content on this forum is meant for the golfer's only perspective and therefore the golfer only needs to filter what they want and don't. Instuctors and researchers alike tune in and find this content valuable.

Steve

A lot of my posts are tongue in cheek but obviously that doesn't always come across on a forum.I wouldn't debate anyone over 10 years of age on physics as I am certainly no scientist.

 

[Steve Greffen]

A lot of my posts are tongue in cheek but obviously that doesn't always come across on a forum.I wouldn't debate anyone over 10 years of age on physics as I am certainly no scientist.

Understood and acknowledged. Your right didn't come accross that way. I do agree that it would be benefitial for the masses (and dumbasses, in intelligence)to have an understanding (if even warranted) on this particular topic. It does come up here on and off and either it is just semantics or something that the scientists need to debate but if it is something that every golf instructor needs to know...I want to pay close attention!

Steve