Centrifugal force and gravity the same?

[Virtuoso]

Gravity is a rate of acceleration downward somewhere between the feet depending on the the body's cg location. Centrifugal force creates a dynamic pulling force (can be measured in lbs) down the longitudinal cg of the club at the bottom of the swing, which can also be defined as a rate of acceleration.

(The dynamic pulling weight is captured on force plate measurements.)

Bad golfers typically fall off the end of their toes and step foward when they lose their balance. It's as if the source of gravity has tilited slightly up and front of them (the resultant force between the ground and the club lcg). They lose the tug-of-war but regain their balance once centrifugal force is gone. The ground has become the only source of "gravity" again.

Good golfers lean backwards against the "tilting earth" and maintain their balance.

Thoughts?

 

[SteveT]

We still don't know what 'gravity' is and Newton declared "hypotheses non fingo" about gravity .. it was just there and downwards ... straight downwards ... so how can the force due to gravity unbalance golfers only ...

 

[mfm22]

It's about maintaining ones posture ..

More interesting is what Brian had mentioned as "Parametric acceleration" I'm wondering if this is similar to when a figure skater pulss arms in and spins faster??

 

[Virtuoso]

It's about maintaining ones posture ..

More interesting is what Brian had mentioned as "Parametric acceleration" I'm wondering if this is similar to when a figure skater pulss arms in and spins faster??

I believe the skater spins faster because he has redistibuted his mass closer to the axis of rotation and thus lowered his moment of inertia.

 

[Dariusz J.]

I believe the skater spins faster because he has redistibuted his mass closer to the axis of rotation and thus lowered his moment of inertia.

Yes. Because there can be no gain or loss in a closed system as per COAM rule. Smaller inertia = bigger velocity and viceversa. But this example have no usage in golf since we create and add energy when swinging.

Cheers

 

[SteveT]

Forget the figure skater ... just tell me how a straight down vertical gravity-related force vector can unbalance a swinging golfer ..??!!!

 

[Michael Finney]

Parametric Acceleration

It was found that, for a mass rotating around a pivot, if the pivot (in this case the club handle) is moved in the direction opposite to the direction of centrifugal force (ringer) of the mass, the kinetic energy of the mass could be increased. The increase is a result of the mutual action of the two governing factors of the system , which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon ******=* and the parameter in the second term (*) of the lefthand side of the equation * characterizes its behavior. The phenomenon is called the parametric acceleration, following the parametric excitation of vibration problems also governed by a similar equation.

Koryo Miura
University of Tokyo
2001

 

[Virtuoso]

Forget the figure skater ... just tell me how a straight down vertical gravity-related force vector can unbalance a swinging golfer ..??!!!

Can the dynamic pulling weight created by centrifugal force "pull" the recreational golfer toward his toes enough to have him lose his balance. Is the ability of good golfers to counterbalance that force a distinguishing characteristic of an advanced golf swing?

Is the resultant force between centrifugal force and gravity a condition that the advanced golfer subconsciously takes into account while swinging?

If the dynamic pulling weight reaches a value of 100 lbs down the club, will bad golfers accidentally let their body cg shift out toward the ball, while good golfers either re-position their mass around their cg to play the tug-of-war, or move the cg back toward the heels to offset centrifugal force?

 

[Ringer]

Parametric Acceleration

It was found that, for a mass rotating around a pivot, if the pivot (in this case the club handle) is moved in the direction opposite to the direction of centrifugal force (ringer) of the mass, the kinetic energy of the mass could be increased. The increase is a result of the mutual action of the two governing factors of the system , which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon ******=* and the parameter in the second term (*) of the lefthand side of the equation * characterizes its behavior. The phenomenon is called the parametric acceleration, following the parametric excitation of vibration problems also governed by a similar equation.

Koryo Miura
University of Tokyo
2001

I'm still waiting for someone to explain how a rotating space/time around the club would cause pull on the club.

You could just simply express it as an increase of centripetal force which causes acceleration on the club. There's no need to state it's in the opposite direction of anything.

 

[Michael Finney]

I'm still waiting for someone to explain how a rotating space/time around the club would cause pull on the club.

You could just simply express it as an increase of centripetal force which causes acceleration on the club. There's no need to state it's in the opposite direction of anything.

I'm sorry you have a tough time with people using the term "centrifugal force". What about applying the term to the way someone "releases" the club?.........It's fictional, it doesn't exist, and it's a release. That has to be taking it to another level for you!

Otherwise, Bob Grober and mandrin both agree on its existence. The guy nmgolfer (I think) thought like you do - it doesn't exist. I'll use an oldie but a goodie for long time manzella-ites.....I'm going to trust the Applied Physics Professor from Yale before I trust a guy from Avondale.

Before you get upset Steve, I'm just poking fun. I understand your point of view - it's hard to fight city hall and the high school physics books sometimes.

 

[savydan]

Can the dynamic pulling weight created by centrifugal force "pull" the recreational golfer toward his toes enough to have him lose his balance. Is the ability of good golfers to counterbalance that force a distinguishing characteristic of an advanced golf swing?

Is the resultant force between centrifugal force and gravity a condition that the advanced golfer subconsciously takes into account while swinging?

If the dynamic pulling weight reaches a value of 100 lbs down the club, will bad golfers accidentally let their body cg shift out toward the ball, while good golfers either re-position their mass around their cg to play the tug-of-war, or move the cg back toward the heels to offset centrifugal force?

+1. I'm thinking that better players somehow account for this and it has to do with how they use the ground and pivot.

 

[SteveT]

Parametric Acceleration

It was found that, for a mass rotating around a pivot, if the pivot (in this case the club handle) is moved in the direction opposite to the direction of centrifugal force (ringer) of the mass, the kinetic energy of the mass could be increased. The increase is a result of the mutual action of the two governing factors of the system , which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon ******=* and the parameter in the second term (*) of the lefthand side of the equation * characterizes its behavior. The phenomenon is called the parametric acceleration, following the parametric excitation of vibration problems also governed by a similar equation.

Koryo Miura
University of Tokyo
2001

All this says is that force vectors are additive .. that is the force that moves the rotative pivot plus the force that is "in the OPPOSITE ..direction of centrifugal force (aka 'centripetal force') ...!!!!

Now all I want somebody to tell me by what mechanism the "force that moves the rotative pivot" is applied ... anybody???

ALSO .. I would like to have the full context reference source to Miura's definition of Parametric Acceleration .. please.

 

[Michael Finney]

if you're ever really, really bored...read a paper about the science of throwing a hammer (olympics not craftsman)

the thrower is constantly maintaining equilibrium as he spins and simultaneously "pumping" energy in to the hammer via the attached cable.....he's trying his best to not fall down and at the same time add energy

 

[SteveT]

Can the dynamic pulling weight created by centrifugal force "pull" the recreational golfer toward his toes enough to have him lose his balance. Is the ability of good golfers to counterbalance that force a distinguishing characteristic of an advanced golf swing?

Is the resultant force between centrifugal force and gravity a condition that the advanced golfer subconsciously takes into account while swinging?

If the dynamic pulling weight reaches a value of 100 lbs down the club, will bad golfers accidentally let their body cg shift out toward the ball, while good golfers either re-position their mass around their cg to play the tug-of-war, or move the cg back toward the heels to offset centrifugal force?

I think your, and everybody else's thinking is bass ackward ... FIRST you lose your balance and THEN you blame the so-called pull of so-called centrifugal force.

That's called "post hoc ergo propter hoc" logic ... and it's fallacious ...

 

[Michael Finney]

All this says is that force vectors are additive .. that is the force that moves the rotative pivot plus the force that is "in the OPPOSITE ..direction of centrifugal force (aka 'centripetal force') ...!!!!

Now all I want somebody to tell me by what mechanism the "force that moves the rotative pivot" is applied ... anybody???

ALSO .. I would like to have the full context reference source to Miura's definition of Parametric Acceleration .. please.

let me google that for you:

Parametric acceleration – the effect of inward pull of the golf club at impact stage - Miura - 2001 - Sports Engineering - Wiley Online Library

download the paper if you can....(you may need to know a college student with a library code) and you can see all his equations and his references - have fun, you lazy bastard

as far as:

the "force that moves the rotative pivot"

you should try steve nesbit - he has a thought or 500 on the subject - i refuse to google that one for you

 

[birly-shirly]

Parametric Acceleration

It was found that, for a mass rotating around a pivot, if the pivot (in this case the club handle) is moved in the direction opposite to the direction of centrifugal force (ringer) of the mass, the kinetic energy of the mass could be increased. The increase is a result of the mutual action of the two governing factors of the system , which are the centripetal force and the pull velocity. A special type of equation of motion governs this phenomenon ******=* and the parameter in the second term (*) of the lefthand side of the equation * characterizes its behavior. The phenomenon is called the parametric acceleration, following the parametric excitation of vibration problems also governed by a similar equation.

Koryo Miura
University of Tokyo
2001

Is this different from Ernest Jones' pocket-knife and handkerchief?

 

[SteveT]

if you're ever really, really bored...read a paper about the science of throwing a hammer (olympics not craftsman)

the thrower is constantly maintaining equilibrium as he spins and simultaneously "pumping" energy in to the hammer via the attached cable.....he's trying his best to not fall down and at the same time add energy

Yes ... that 'maintaining equilibrium' is just maintaining the pivot, because if the pivot moves too much you will lose your balance and fall down. Please don't blame that on "centrifugal force' which may not exist if you try to correctly draw and calculate that force vector. (Where is mandrin hiding now ... I'm calling him out and he's MIA .. I hope he's well.)

Now tell us something we don't know ... like Parametric Acceleration and how it's applied in the golfswing.

 

[Michael Finney]

Yes ... that 'maintaining equilibrium' is just maintaining the pivot, because if the pivot moves too much you will lose your balance and fall down. Please don't blame that on "centrifugal force' which may not exist if you try to correctly draw and calculate that force vector. (Where is mandrin hiding now ... I'm calling him out and he's MIA .. I hope he's well.)

Now tell us something we don't know ... like Parametric Acceleration and how it's applied in the golfswing.

Nesbit already has - and if you're any good at golf, you probably already do......

 

[SteveT]

let me google that for you:

Parametric acceleration – the effect of inward pull of the golf club at impact stage - Miura - 2001 - Sports Engineering - Wiley Online Library

download the paper if you can....(you may need to know a college student with a library code) and you can see all his equations and his references - have fun, you lazy bastard

as far as:

the "force that moves the rotative pivot"

you should try steve nesbit - he has a thought or 500 on the subject - i refuse to google that one for you

If you can't provide the proper protocol when you are quoting definitions, it's you who is 'lazy'.

Instead of depending on gratuitous quotations from unknown sources perhaps you can ask Steve Nesbitt to provide you with a force vector free body diagram that illustrates your Parametric Acceleration ... otherwise please don't just throw faux-scientific grenades that are duds .. and then getting your back up because you can't back up what you post when challenged.

Good science is also confrontational science done in a proper manner ... "just prove it" ... that's all I ask of you.

 

[gmbtempe]

let me google that for you:

Parametric acceleration – the effect of inward pull of the golf club at impact stage - Miura - 2001 - Sports Engineering - Wiley Online Library

download the paper if you can....(you may need to know a college student with a library code) and you can see all his equations and his references - have fun, you lazy bastard

as far as:

the "force that moves the rotative pivot"

you should try steve nesbit - he has a thought or 500 on the subject - i refuse to google that one for you

thank you so much for linking that