Conservation of Angular Momentum . . .
 

What is it? How does it function in a golf swing? Is it useful for both methods of accelerating the club (hitting and swinging)?

I think this is an important topic . . . but I'm not really qualified to discuss the physics aspect because of the genetic crap shoot and all.

The short answer is that it is harder to move a long lever than a short one, but a long lever can provide more force for a given amount of speed.

COAM is effectively keeping a long lever, as short as can be while building speed by creating angles, and then as long as can be by releasing those angles at the proper time for the application at hand.

Physics 101 Answer
 

Well, here is what happens when clubhead meets ball. This may not mean much relative to swing, but it will give everyone something to start with.

Mball * Vball_after + Mclub * Vclub_after = Mclub * Vclub_before (the before and after refer to impact)

Basically, since this is an elastic collision, momentum is not strictly conserved, but it is close enough for our purposes. You can also approximate Mclub with the mass of the clubhead alone since the impact interaction occurs over such a short time.

How about this Bosslady . . . So the primary lever assembly moves in a circle regarless of how it is driven huh? what? So that would be the case on the backstroke . . . smell me? So there is a certain amount of inertia of the club moving back. Then the player changes directions . . .

At this point is this where the whole deadweight inertia draggin' lil' bruva of clubhead lag pressure point pressure is loaded?

So then what? You continue to spin the flywheelz (dubz) or do you drive the stump?

Is the swinger manipulating Angular Momentum? While the Hitter is overcoming it by driving in a straight line?

What do the physics types say?

Newton's 1st Law
 

You're killin me. Basically, lag is a consequence of Newton's 1st law: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. As you start the club back (overcoming inertia - bonus points in this discussion and probably a Nobel prize if you can give definitive explanation why mass exhibits inertia :eyes: ) you impart momentum to the club, i.e., put it in motion. When it is time to start the downswing, this motion must be overcome with a force to get the club moving downplane towards our dimpled friend (the ball, not Bucket's Behind). When that force is applied, one feels lag pressure. As long as that force is continually applied, the lag pressure will remain. Lag pressure maintained through impact will result in a collision that is more inelastic (less lossy) than if one had a clubhead moving with a constant velocity (my assertion, et al.).
Once again, I probably am not providing the answers folks are looking for. Sorry if that is the case.

Yo homegirl my butt gettin' big . . .
 

PERFECT! Thus . . . SUSTAIN the the LAG not INCREASE the LAG. Now what do you say about "lag is a consequence of Newton's 1st law: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it." . . . for a Hitter. If we have applied thrust via the turning of our body (phat donkey and all) . . . AND THEN one's Right Tricepts takes over have we annulled "the conservation of angular momentum" as a result? Would you say the Physics are different as a result of the Right Arm supplying the "thrust" or "acceleration" or whatever?

How'd you know my hiney had dimples? Beware "Killing me." Mikey is LURKING. He forgets his medication sometimes.

Tread lightlly
 

Steph can handle herself- but tread lightly BucketHead- there's a lady in the house!

Lag- Resting on a Rock Solid Foundation
 

Ah, Life is good!

Steph, we'll need to get that put in the 8th edition!:)

Force is Force
 

Applied force is applied force. As long as the lag pressure is felt at PP3 throughout the down (out and forward) stroke, then the Hitter is still applying force. However, if one plotted lag pressure vs. time during the down stroke, then one might see variation as different components dominate as the force appliers.

Actually, some of the more advanced swing analysis places measure and plot clubhead acceleration during the golf stroke. It is an eye opening and humble experience. The Titleist Performance Center folks probably do it. Don't forget, acceleration makes the world go round. :-k :toothy1:

Witcha . . . but . . . is the force that the Hitter applies the same as Angular Momentum? Or is he overriding it as a result of trying to thrust in a straight line?

Thanks for bearing with me . . . there were some cousins who "got together" in my lineage.

Cause vs Effect
 

Force is cause. Applying force results in movement. Angular momentum is effect. Mass moving about a fixed point has angular momentum. Applying force (cause) results in the club acquiring angular momentum (effect).

Closely related family members "getting together" (cause) results in (somewhere along the family tree or evolutionary tree - your pick) Bucket (effect). ;-) See you already understood the concept, but just had not applied it to the physics (wasn't this easy)!:p

Merry-Go-Round -- Push or Pull
 

Very nice, Steph. That concise explanation helps us all.

Bucket, with Steph's description in mind, think of pushing a playground merry-go-round into its rotating motion. The straight line thrust (force) causes the merry-go-round (the mass rotating about a fixed point) to acquire its rotating motion (and hence its angular momentum).

The straight-line 'push' is against the centripetal force of the merry-go-round's fixed structure, and as a G.O.L.F. analogy, is a Hitting Motion.

Similarly, the identical angular momentum could be created by turning the axis of the merry-go-round, thereby inducing a centrifugal force and its 'pull'. This is analagous to the Swinging Motion.

The far end speeds up when the radius gets shortened, and vice versa, which could be manipulated to regulate the clubhead speed.

I'm, however, not aware of COAM for clubhead manipulation, I strictly manipulate "lag" (or "club weight" or "shaft bent/stress") in swinging, hitting or snapping.

Apology
 

Bucket,

I want to apologize. I completely missed the "angular" in your question. I was so concentrated on conservation and momentum, that I answered the wrong question. I literally went off on a tangent. :laughing9

Angular momentum is a bit difficult to get a handle on in the golf stroke because you have 3-dimensional motion of an assembly that can be roughly approximated by a double pendulum. Here are some references which you might find interesting: http://hyperphysics.phy-astr.gsu.edu/hbase/amom.html, http://scienceworld.wolfram.com/phys...ePendulum.html.

I like this example - it shows why tempo - transition, and gravity are important - the ratio of back to through in time.

Chaos
 

The double pendulum is an example of a "simple" system whose motion results in chaotic behavior. Thus, the similarity of the golf stroke is not surprising.

Looks like my stroke of late:(

Ah, but this can lift some fog for any true swinger IMO

The image shows you why there have been many who speak of 'complete the backswing' or 'pause at the top' or 'wait for it' as transition swing keys.

The image shows you what happens if you start down too quick/too soon - throwaway ;)

There are also some lessons here for the aiming point concept.....and loading

One of the reasons I love the Tour Tempo sounds - they show you how to make sure you don't start down too soon - how to let gravity help you with your timing so that 'lower pendulumn' doesn't out race the upper and throw the club away.


I suspect many may dismiss this as a minor point - but if you are a swinger, a very, very important image to understand (why this shows a bad example, and what a 'true swing' would need to be for there not to be throw away)

Steph - do you know the calculation which would show what the ratio of back to through would need to be (in time) of the primary pendulumn for the secondary pendulumn not to have throw away (until about 7-8 o'clock as 'in line')? Just curious if my understanding of a 3 to 1 ratio (pi) is correct.

Experimentally Derived
 

Ed,

I think the Tour Tempo 3 to 1 factor was experimentally or observationally derived. It would not be easy to solve the double pendulum equations to arrive at that ratio. Basically, that double pendulum figure is being driven strictly by gravity. There are no other forcing functions. In the golf stroke with forces active during takeaway and the down swing, it gets very complicated to derive timing ratios like you are looking for. Someone may have done it, but I am not aware of such work. Sorry.

COAM is not something you CAN manipulate.
COAM is what happens on the way to the ball
Conservation of Energy is what happens at the ball


Part 1. Angular momentum is about what happens on the way to the ball. Whether you hit, swing, push or pull, angular momentum is going to be conserved regardless of what you do. However, the more you can sustain the lag, the more momentum has to be generated on the other side of the equation (i.e. transferred into the ball) for momentum to be conserved. What happens is that you start out with a large center of rotation (big wheel) of the club generally around your left shoulder. As you rotate down the plane and sustain the lag, you are shifting the primary center of rotation of the club to a point in your hands (small wheel), The longer you sustain the lag, the smaller the small wheel, and like the ice skater pulling in her arms, the faster the clubhead mass must travel to conserve angular momentum. Thus, the clubhead arrives at impact with an amount of kinetic energy, which like momentum is conserved.

Part 2. If you think about the impact interval being only a fraction of an inch or so, you can essentially consider this segment of the swing arc as a straight line, and thus, the collision between the ball and the clubhead is about the conservation of energy. The clubhead developed a certain amount of kinetic energy (1/2 m*v^2) during the pre impact interval, and some of that is going to be transferred to the ball through the collision. As Steph mentioned, the collision is elastic and there are some small losses associated with deforming the ball, and the clubface, but these are small. The efficiency of the energy transfer between the clubhead and the ball is related to the purity of contact, meaning mostly contact along the line of compression/direction of flight. Energy is lost to creating spin. Much of the energy is transferred to the ball. So, the simple balance is: (1/2 m1*v1^2 - losses)(clubhead) = 1/2 m2*v2^2.(ball)*

So what this is all about is creating the maximum kinetic energy just prior to impact. Sustaining the lag as long as possible creates the smallest center of rotation, and thus the maximum velocity since the clubhead mass didn't change. Hit, swing, push, pull, these principles don't change.

*Note: this is not rigorously correct since the impact interval is a slight arc, and not a precisely straight line. However it is pretty close.

G2M

?
 

I'm now starting to think that EDZ is also 12 piece Bucket- either way when bucket starts a thread it inevitably slopes downhill. I was memorized today for four hours watching this thingy move- then went out on the par 3 course and shot 172! Ed have you got another thingy that can de-program my throwaway problem!!

No kidding! I saw that same thing once on a hair-lipped stripper in Tupelo . . . I got "memorized" too.

I think I remember her.... but the one I saw had two of 'em...did yours only have the one?

Naw she was more talented than that . . . she had 3.

A broom or a mop ;)