Brian,
For the dumbos amongst us, could you clarify the procedure (physical input or otherwise) needed to, "snap the kinetic chain"...thanks
Lag Pressure Talk
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Brian,
For the dumbos amongst us, could you clarify the procedure (physical input or otherwise) needed to, "snap the kinetic chain"...thanks
mandrin
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Lag is not cause but the result of applying force/torque on the butt end of the club shaft.
This is indeed a tenacious myth. A golfer can not transfer his mass into impact, only exert force/torque via the shaft prior to impact. During impact itself the golfer's efforts have a negligible effect and can be ignored.
mb6606, clubhead lag is only present during the first portion of the down swing when one sets the down swing into motion. Subsequently the centrifugal inertial torque gets into the act, and the club starts to overtake the angular velocity of the arms, striving towards the inline condition.
Henceforth any apparent feeling of lag with pp #3 is not caused by inertial lag but simply by chasing the shaft with the forefinger fast enough to give the feeling of pressure. It can’t be defined as lag pressure being caused by muscular action of the trail hand chasing the “fleeing” shaft.
Mandrin,
If the hands increase acceleration throughout the first part of the downswing, doesn't that result in prevention (or reduction of achievement) of the shaft in-line process?
Therefore wouldn't pp#3 be not be chasing the shaft, but actually resisting increased lag angle, until the acceleration slowed and the shaft could catch up, hence the bowed shaft condition you see on still photos?....
mandrin
New
puttmad,
I did not mention in my post that the hands increase acceleration throughout the first part of the downswing but instead that any pressure felt at pp#3, during the second part of the down swing, is due to chasing the shaft.
In general, whatever the golfer does, if he has a reasonable sound dynamic down swing, the club will always obtain inline condition somewhere around impact due to the dominating centrifugal torque. Any wrist torque will not much affect clubhead velocity but influence primarily position of hands at impact.
The physics of a down swing dictate that there is first an inward inertial torque exerted on the shaft followed by an outward inertial torque. Therefore one can speak of clubhead lag only for the first part of the down swing but not for the second part. If one feels pressure with pp #3 during the second part than it is caused by actively chasing the shaft.
Mandrin, what do you think of the initial premiss? The lag is a form of creating accelleration through angular change rather than actual thrust.
I forgot to ask..
Can the same amount or even an increased amount of thrust be performed but still have the hands slow down because of the effect you describe?
mandrin
New
Ringer,
I don’t feel that we are quite taking lag to mean the same thing. Lag means to delay, to stay behind. Hence lag is not an action but instead it qualifies a situation.
If you torque a whippy shaft the head tends to stay behind, it lags. However, a pulling/pushing force exerted on the butt end of the shaft - if there is an angle between the shaft and the direction of pull/push - will also generate a torque and hence result in lag for the clubhead.
Therefore in general both a linear force and a torque exerted on the butt end of the shaft produce angular acceleration and generate clubhead lag. See Jorgensen’s ‘five experiments’, in “The Physics of Golf”, for an interesting discussion of linear force producing torque in the golf swing.
mandrin
New
Ringer,
Forces and torques are vector quantities which can be added or subtracted.
We all know from experience that it is not feasible to prevent the club from releasing. There is indeed a very large inertial torque operation on the shaft and as soon as the golf club releases the hands/arm will slow down a certain amount.
If you, the golfer, exert torque through the triangle during the release, this will have an effect to what extend that the hands slow down. For instance, a golfer primarily activating his swing early from the top will have his arms/hands slow down more than someone starting slow and accelerating from thereon.
mandrin
New
Ringer,
Could you explain a bit more what you feel is changing direction during impact interval?
The veloicty of the clubhead.
...
Steve, I don't think velocity changes direction (speed is not directional...
), but what does change is the angular relationship of the clubshaft to the left arm, thus changing the distance from the left shoulder to the clubhead, thereby altering the clubhead arc (changing from a wrist fulcrum to a shoulder fulcrum) and increasing its velocity ...
Steve, I don't think velocity changes direction (speed is not directional...
), but what does change is the angular relationship of the clubshaft to the left arm, thus changing the distance from the left shoulder to the clubhead, thereby altering the clubhead arc (changing from a wrist fulcrum to a shoulder fulcrum) and increasing its velocity ...
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Puttmad, I'm not sure what you're under the impression of. Velocity is a measurement of speed AND direction. Therefore if you change the direction, you change it's velocity and that change is known as accelleration. You're right though, the RADIUS of the swing extends if measured from clubhead to left shoulder. But accelleration occurs because the clubhead changes direction. This is true of any object that is moving in a non non-linear motion.
Bigwill, many many many physics instructors would beg to differ.
"Velocity is a vector quantity. As such, velocity is direction aware. When evaluating the velocity of an object, one must keep track of direction. It would not be enough to say that an object has a velocity of 55 mi/hr. One must include direction information in order to fully describe the velocity of the object. For instance, you must describe an object's velocity as being 55 mi/hr, east. This is one of the essential differences between speed and velocity. Speed is a scalar quantity and does not keep track of direction; velocity is a vector quantity and is direction aware."
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/1DKin/U1L1d.html
"Velocity is a vector quantity. As such, velocity is direction aware. When evaluating the velocity of an object, one must keep track of direction. It would not be enough to say that an object has a velocity of 55 mi/hr. One must include direction information in order to fully describe the velocity of the object. For instance, you must describe an object's velocity as being 55 mi/hr, east. This is one of the essential differences between speed and velocity. Speed is a scalar quantity and does not keep track of direction; velocity is a vector quantity and is direction aware."
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/1DKin/U1L1d.html
I'm truely lost where we differ. Velocity changes with either speed, direction, or both.
I get the feeling that we're differing on terminology, and the specifics of that terminology.
As far as velocity and acceleration goes, they're not, in the most strict sense, directly related to change of direction. In short, speed is how fast something is going, whether it is moving away from its starting position or not. Velocity measures the rate tha something is moving away from its starting point. When you have a change in direction, then there are two separate velocities involved; the one before the change of direction, and the one after. Acceleration is the rate of change of a velocity, ie the rate that something is speeding up or slowing down. If you change directions, then you introduce a different vector. In reference to the clubhead during the swing, there's a vector that represents the velocity or acceleration of the backswing, then a separate vector to express the same for the downswing. So the change of direction, from a physics standpoint, marks the starting point from which you would measure the downswing acceleration of the clubhead. The definition of acceleration dosen't include the change of direction.
mandrin
New
Ringer, I wonder if your are inventing a new kind of dynamics.
Let’s have a closer look and see if we can sort things out.Not letting the angle open up till late in the down swing (sustaining the lag) will help obtaining a large clubhead velocity at impact.
During the about 0.7 inches that the ball and clubhead travel together for 0.0005 sec the clubhead loses a fair percentage its speed.
There is no rapid change of direction during the impact interval, only a very sudden and large deceleration of the clubhead.
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