drewyallop
New
Mandrin,
I believe he is referring to this diagram that MJ posted earlier in a different thread.
That is it Mandrin.
Drew
Mandrin,
I believe he is referring to this diagram that MJ posted earlier in a different thread.
Drew,Mandrin,
Thanks for the work on parametric acceleration.
I am having trouble understanding the diagram from the Miura paper that Mike Jacobs posted here. If you have time would you provide a fuller explanation? Specifically, what are hands doing during the periods of tangential and centripetal force shown in the the diagram.
Thanks,
Drew
Mandrin I have a question what happens when a small mass that is connected via a rope, chain or arms and hands , to a large mass goes/travels in the opposite direction that the larger mass wants to travel in? Does the large mass travelling in a different and opposite direction exert a pulling force on the small mass and win the tug of war?
Also if they were travelling in opposite circular directions would the small mass catch up to the large mass if the large mass suddenly or slowly came to a stop? How about if the large mass wasn't moving and a small mass travelled around it and then the larger mass started to move in the opposite circular direction, what would happen?
footwedge,
You have to give a bit more specific information for me to be able to give an answer to your questions. It looks like you want to learn more about particle mechanics.
Drew,
The diagram you refer to is not from Miura but rather from Dr. Williams, the first golf scientist.
The forces, as shown in the diagram you referred to, are those calculated by Dr. Williams, based on the golf swing of Bobby Jones, using a driver. The diagram show the tangential and centripetal force component in the down swing. You ask what are the hands doing? The answer could be as simple as that they are really simply holding on and not exerting any active torque. If you start the down swing dynamically than eventually inertial forces take over and diligently run the show.
Look at Figs 1a / b and Figs 3a / 3b where the same information is displayed as in Williams' figure. They are quite similar in nature. However the simple overall picture is that very soon from the top the force acting through the wrist joints aligns itself along the club shaft and remains so for the remaining of the down swing. Therefore initially this force is tangential to the hand path and closer to impact virtually normal to the hand path.
I like to mention that showing the forces/torques, such as determined either in a math model or measured, can be quite confusing for the average golfer. When showing such derived forces acting through the wrist joints one could quite likely take this for the actual forces/torques exerted directly by muscles of wrist and hands. However these forces/torques are largely determined by the dynamic interaction of arms and club, hence inertial forces/torques. We are, for instance, barely aware of the large centripetal force developed being too short in duration.
Thank you mandrin.
I will check out the figures you suggest.
I don't think you have the provenance of the diagram correct. There is a citation at the bottom of the diagram that leads to the Miura article in "Sports Engineering", here: Sports Engineering - Volume 4, Issue 2 - May 2001 - Wiley Online Library
Drew
ALL OF NESBIT"S WORK WE ARE USING IS 3D.
3D.
Why do you think Brian and the scientists don't understand the difference between 2D and 3D? Because of that one model that was discussed earlier? He already answered that is just one model used in their research. As Brian said there is a lot of information that he has not talked about yet.
That not what he is saying. TeeAce can defend himself but he is simply asking about the way the measurement have been done. He seems to own a lot of data and explained that in the process of trying to extract information out of the data he found out that you need to pay attention how you measure angles.
If the Bman team is willing to answer his question he then is able to compare his information with the information that has been shared here freely by the Bman and his team. And as far as I can tell from his posting he is even willing to share his data and knowledge here as well.
That all, a simple question of the procedure used to measure the angles.
Drew,
I verified and indeed it is Miura and not Williams. Recently seeing a figure in 'The Dynamics of the Golf Swing' by Williams, with a similar way of presenting forces, is likely the reason for the confusion. I dislike making this kind of mistakes but memory is a faculty which does not always perform as desired.
spktho,Very nice diagrams and graphs illustrating a closer to real golfer parametric acceleration.
Would the acceleration of the club head be different from the swing center moving horizontal forward if the swing center moved horizontally backwards?
Backward motion gives a somewhat greater clubhead speed re to forward motion of center.
spktho,
Forward...............51.55 m/s
Zero....................51.57 m/s
Backward.............52.01 m/s
Backward motion gives a somewhat greater clubhead speed re to forward motion of center.
If you are particularly interested I could produce the figures as well, but give me some time.
Interesting, and this may explain why some of the pro and LD golfers seem to rear back with their shoulders through impact, while their hips have cleared and moved forward.... as they lash out at the ball. Go figure ...
Jon,I had a hunch also that this would increase clubhead speed...
Mandrin, could you expand on swinging left adding to clubhead speed? I think this component doesn't get the attention that it deserves.
Thanks again for all your contributions on this site. Much appreciated.