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Post by dubiousgolfer on Aug 1, 2019 9:34:19 GMT -5
Dr Mann I've been searching the internet about D'Alemberts principle and its nothing to do with physics but a mathematical manipulation used to make the maths easier. Its a way to convert complex dynamic equations of a rigid body (using real forces) to simpler static body equations (using fictitious inertial forces such as the Centrifugal and Coriolis force). www.youtube.com/watch?v=75wAxMoXYfYTo explain 'release' using D'Alemberts principle means also inviting the use of fictitious forces. DG
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Post by imperfectgolfer on Aug 1, 2019 20:54:49 GMT -5
Dr Mann I've been searching the internet about D'Alemberts principle and its nothing to do with physics but a mathematical manipulation used to make the maths easier. Its a way to convert complex dynamic equations of a rigid body (using real forces) to simpler static body equations (using fictitious inertial forces such as the Centrifugal and Coriolis force). www.youtube.com/watch?v=75wAxMoXYfYTo explain 'release' using D'Alemberts principle means also inviting the use of fictitious forces. DG I really don't understand physics so I don't know what he is talking about in that video. If you disagree with nmgolfer's opinions in the following link, feel free to criticize it. nmgolfscience.tripod.com/release.htmJeff.
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Post by dubiousgolfer on Aug 28, 2020 21:53:26 GMT -5
Now I understand exactly D'Alemberts principle as per nmgolfers link. D'Alembert's principle says: the resultant motion of a rigid body is completely defined by the resultant and moment resultant about the mass center of the external forces acting on it. nmgolfscience.tripod.com/img/fig3.pngAs you can see the rotating circular arrow is about the COM (ie. club rotating around it). It was easy to assume that the rotation was happening around the handle because that's how we perceive a real golfers swing and its unfortunate to realise (a few years too late) that these 'decomposed simplified' maths has no bearing on the reality of the golf swing which requires the COM to be accelerated. It might explain how the spinning handle might uncock the wrists but that doesn't fit into a pragmatic explanation of the release of PA#2 (which requires the COM to orbit around the hands). Didn't nmgolfer (and Mandrin) realise that the twirling of the club like a 'baton' (as proven by their maths ) seems highly improbable in a real golfers swing mechanics? Also note that the circular arrow in the above image is in a 'clockwise' direction , but the 'moment of couple' would actually be in the anti-clockwise direction . I think he was just showing the convention used for a 'moment of couple' vector direction using the right hand rule (ie. a clockwise direction of rotation would mean the 'moment of couple' vector pointing into the page). DG
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