Well no... energy is not stored (or conserved). The golf swing is not very efficient. We do the backswind to establish "potential" energy ....a small amount of gravitational rho*g*h and a whole lot of musclar-skeletal "P.E.". The backswing is like putting "fuel" in the muscular-skeletal engine.
The stored energy I was referring to - its's nothing more mysterious than the swing speed at any time of the downswing. To be picky it's mass * speed^2 but it basically deals with the gradually build of swing speed throughout the down stroke.
This is very basic fysics. And perhaps the point is so self-evident that you looked for something more "exotic" in my statements.
Quote:
Once the downswing begins muscles fire, the linkage begins moving and eventually some 22% (Nesbit) of that potential energy gets converted into Kinetic energy (1/2 m V^2) concentrated at the head of the club. None of it really ever gets stored (for long) or in a benificial way (i.e. club shaft bend doesn't help us).
The kinetic energy you are mentioning here is what I am basically conserned with. You are correct that it doesn't get stored for long. A significant part of it is spent at impact and the rest is wasted shortly after.
Quote:
Like Wishon I believe "shaft kick" is a myth.
I have a really *big* problem seing how extensior action can be executed without loading the shaft. And shaft that is being loaded will reload when the moment is off.
Quote:
Now setting all of this aside.....
It is quite possible in the "optimal" (if there is such a thing) golf swing there is a point on the golfer's body that remains steady (motionless). I have no problem with people calling that a swing center or what ever as long as they realize is highly unlikely that this spot is where "centripetal force" gets directed for anything other than an instant and probably then just by coincidence.
The two-lever system complicates things. But if you're driving the primary lever around a quiet center - and if the primary lever is driving the secondary lever - I think it makes sense to speak of a swing center.
Further, I do not see a significant upside in moving this swing center around much.
Good golfers + instructors introduces all kind of "tricks" to hit the ball furter. And a lot of ordinary golfers gets confused. X-factor, late release and your "jump on your toe" by the end.
The reason I think the concept of work and energy storage is important in understanding the golf swing because:
1) As long as we can (more or less) accumulate energy until impact, it doesn't matter whether we energize the swing early or late. I don't regard the "late hit" as a magic formula for increased distance for instance.
2) Not even the purest swing is all about centripetal acceleration. Centripetal acceleration only helps us store the energy. We need to actively rotate mass to build swing speed. Tangential forces must be applied. Centripetal acceleration feels powerful but it doesn't add power.
3) A lot ofthe magic mystery moves that is supposed to increase swing speed is misleading.
A stroke pattern that enables the golfer to apply max tangential forces throughout, and at the same time provide the required centripetal force to carry the m*v2 until impact is as good as it gets as far as swing speed is conserned. If that doesn't produce enough swing speed it's time to hit the gym.
I don't know "fysics" but I do know PHYSICS and to be very picky in this case speed and velocity are synonymous. You say speed I say velocity we get the same answer.
Energy doesn't get banked (stored ... dollars in an account) ... the downswing converts potential energy to kinetic. Forces across levers create movement.... that's kinetic energy.
As for the rest... you are entitled to your beliefs. Some people never stop believing in Santa Claus or the tooth fairy. Now we must now agree to disagree.
Originally Posted by BerntR
nmg,
The stored energy I was referring to - its's nothing more mysterious than the swing speed at any time of the downswing. To be picky it's mass * speed^2 but it basically deals with the gradually build of swing speed throughout the down stroke.
This is very basic fysics. And perhaps the point is so self-evident that you looked for something more "exotic" in my statements.
The kinetic energy you are mentioning here is what I am basically conserned with. You are correct that it doesn't get stored for long. A significant part of it is spent at impact and the rest is wasted shortly after.
I have a really *big* problem seing how extensior action can be executed without loading the shaft. And shaft that is being loaded will reload when the moment is off.
The two-lever system complicates things. But if you're driving the primary lever around a quiet center - and if the primary lever is driving the secondary lever - I think it makes sense to speak of a swing center.
Further, I do not see a significant upside in moving this swing center around much.
Good golfers + instructors introduces all kind of "tricks" to hit the ball furter. And a lot of ordinary golfers gets confused. X-factor, late release and your "jump on your toe" by the end.
The reason I think the concept of work and energy storage is important in understanding the golf swing because:
1) As long as we can (more or less) accumulate energy until impact, it doesn't matter whether we energize the swing early or late. I don't regard the "late hit" as a magic formula for increased distance for instance.
2) Not even the purest swing is all about centripetal acceleration. Centripetal acceleration only helps us store the energy. We need to actively rotate mass to build swing speed. Tangential forces must be applied. Centripetal acceleration feels powerful but it doesn't add power.
3) A lot ofthe magic mystery moves that is supposed to increase swing speed is misleading.
A stroke pattern that enables the golfer to apply max tangential forces throughout, and at the same time provide the required centripetal force to carry the m*v2 until impact is as good as it gets as far as swing speed is conserned. If that doesn't produce enough swing speed it's time to hit the gym.
Last edited by no_mind_golfer : 12-24-2008 at 12:20 PM.
BerntR
Energy doesn't get banked (stored ... dollars in an account) ... the downswing converts potential energy to kinetic. Forces across levers create movement.... that's kinetic energy.
Oh really ......
Energy storage is a very essential topic in a lot of mechanical engineering subjects like noise control and vibration damping. Transducer technology is a subject I know pretty well where energy storage is an essensial challenge. In many cases the efforts are about minimizing energy storage. In other cases it's about tuning. Typical efforts to reduce energy storage in mechanical systems is to reduce mass and add mechanical resistance.
Energy storage is often described with a Q-factor that deals with the ratio of reactive (energy-storing) components to resistive (energy-dissipating) components. http://en.wikipedia.org/wiki/Quality_factor
The down swing converts potential energy (related to g) to kinetic energy, that's true. In addition it stores the kinetic energy that is added by the player working the club. Moving mass is one of the essential ingredients. Most of the mass in the clubhead is there to help the player accumulate energy until impact.
Rsheehy & packard are the only two worth reading...
While edification is generally speaking elusive golf forums provide endless amusement....
Here we have Jeff, who is completely clueless about simple physics terms and absolutely refuses to admit it (and he refuses to read links), spinning aimlessly. And then there is you BrentR whom I strongly suspect is just yet another poser.
You see scientists and engineers know the word is PHYSICS not fysics... they would NEVER make that blatant mistake or many of the others that scream out in your posts. Scientists and engineers generally make sense when they write and you don't.
Nevertheless BerntR I suspect you do know a tiny little bit about transducers (got a job as an aid in a lab did you?) ... I suspect you may even know a tiny little bit about vibration measurment or perhaps acoustics and you are trying to transfer that modicum of superficial extremely cursory knowledge to "your" analysis of the golf swing. This is why we see you tossing out of big sounding totally irrelevant, totally inappropriate terms like "harmonic" or "q factor". See when all you have is a hammer everything looks like a nail... when you are a surgeon the only solution is to operate.
Well guess what.... the golf swing is a gestalt... an event... it is not an oscillating system with or with out damping. Try again BrentR...YOUR MODEL DOESN'T FIT! No energy is stored in the golf swing anytime anywhere.
Oh BTW merry Christmas!
Originally Posted by BerntR
Oh really ......
Energy storage is a very essential topic in a lot of mechanical engineering subjects like noise control and vibration damping. Transducer technology is a subject I know pretty well where energy storage is an essensial challenge. In many cases the efforts are about minimizing energy storage. In other cases it's about tuning. Typical efforts to reduce energy storage in mechanical systems is to reduce mass and add mechanical resistance.
Energy storage is often described with a Q-factor that deals with the ratio of reactive (energy-storing) components to resistive (energy-dissipating) components. http://en.wikipedia.org/wiki/Quality_factor
The down swing converts potential energy (related to g) to kinetic energy, that's true. In addition it stores the kinetic energy that is added by the player working the club. Moving mass is one of the essential ingredients. Most of the mass in the clubhead is there to help the player accumulate energy until impact.
Last edited by no_mind_golfer : 12-25-2008 at 06:02 PM.
Instead of calling me clueless, why don't you use your superior knowledge to point out the errors in my understanding of the term "centripetal force". There are many other forum members who could benefit if you share your knowledge in a constructive fashion - by demonstrating my faulty reasoning.
Consider my understanding of the term "centripetal force".
In a previous post (#264) I wrote the following-: "Imagine that there a million points on that hypothetical circle's circumference, and imagine that an orbiting object (traveling at a constant finite speed) has to move from from one point on the circumference to the next point on the circumference to the next point on the circumference -- and that it has to complete this process one million times to complete one orbit. In each of those movements (from one point to the next point), the orbiting object needs a tangential force to move it at its constant "finite" speed and a centripetal force to keep it moving on the circular path."
Now, consider the following diagram.
I mentioned that one could mentally picture that there a million time-points that the orbiting object will pass through on its circular orbit around one circumference of the circle in one second.
Now, imagine that the orbiting object is at point A. Then, one millionth of a second later the object is at point C.
What forces are in play to move the orbiting object from point A to point C, and do those forces involve the use of energy?
I believe that two forces are in play. The first force is a tangential force that moves the object in a straight line direction with enough energy to keep the object traveling at the same speed. In one millionth of a second, if that tangential force was operant, and no centripetal force was present, then the object should end up at point B (having traveled in a straight line at a 90 degree angle to the circumference of the circle).
If the orbiting object ends up at point C, then we can reasonably conclude that a centripetal force is present. What did that centripetal force actually do? I think that the centripetal force applied centripetal acceleration that moved the orbiting object more inwards (towards the center of the circle) so that it ends up at point C instead of point B. The centripetal force, in theory, should direct the orbiting object to the center of the circle. However, the amount of energy that the centripetal force has is only sufficient to bend the path of straight line movement of the orbiting object enough to get it to point C in one millionth of a second - in other words, the centripetal force has enough energy to keep the orbiting object traveling on a constant circular path. The centripetal force when operant is manifesting its force (energy) and it is therefore doing work to get the orbiting object to end up at point C instead of point B.
I found your response rude and insulting. It's certainly not something I am used to from people with scientific pretensions.
The Q-factor I linked to is more relevant to the the discussion than you seem to have comprehended:
Physically speaking, Q is 2π times the ratio of the total energy stored divided by the energy lost in a single cycle or equivalently the ratio of the stored energy to the energy dissipated per one radian of the oscillation.[1]
If we can exclude all the working forces and just "hold on to the rope" prior to impact we can actually measure the q-factor of the swing. It would be a function of swing speed reduction per degree of rotation. But of course, the experiment must be led by someone who knows how to measure the stored, kinetic energy.
Here's another example of an energy storage device based on rotating mass. I've never heard of it before. I simply googled for something more similar to the golf swing:
The flywheel energy storage accumulates energy by rotating mass up to speed. Kinetic energy in the form of 1/2mv2. If you don't see that the same thing happens in the golf stroke then your understanding of physics and mechanics has serious flaws.
Hybrid Mode
