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Post by imperfectgolfer on Dec 16, 2011 14:31:30 GMT -5
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Post by nmgolfer on Dec 16, 2011 15:01:05 GMT -5
No.... its utter garbage. See my post in the other thread. I'll have more later or perhaps wait to see if BerntR rips it to pieces.
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Post by nmgolfer on Dec 16, 2011 15:02:48 GMT -5
PS just saved it as pdf so we have a record when he deletes the link
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Post by richie3jack on Dec 16, 2011 16:03:29 GMT -5
PS just saved it as pdf so we have a record when he deletes the link Well played, sir. ;D 3JACK
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Post by nmgolfer on Dec 17, 2011 0:23:40 GMT -5
OKey Dokey.... I see whats happening here. Me suspects El mandrino de la mancha has taken to plagiarism yet again. Earlier today when pressed for time took a glance at his first pic in that latest CFD and said what ta hey??? thats the exact opposite of the way kids play (on a swing set). But it is a representation of the Wirkus/Rand/Ruina pumping while standing model that mandrin of la mancha has depicted. Here is the original source, their very well done paper detailing swing set "pumping" mechanics: www.math.cornell.edu/~rand/randpdf/swing.pdf(BTW Its the first thing that comes up in a playground swing mechanics google search, is quite different than mandrin's first treatment of pa and undoubtly what mandrino glommed onto this time and is attempting to pass off as his own, once again there's no attribution.. bad bad just plain bad) But there is another important point to be made....Wirkus/ Rand/ Ruina never once mention centripetal force in their paper. Why ?Because it because it does not apply. What does apply is conservation of angular momentum. Each time the crouching swinger stands up, at the nadir of the swing, when angular velocity is maximum, its equivalent to a sudden decrease in the swing radius hence the angular velocity increases commensurately and the swinger reaches new heights with each passing cycle. The swinger's leg muscles do work (and that ain't centripetal force) which move the pendulum mass closer to the swing center causing an increase in the angular velocity. Think about our hammer/nail/nut experiment detailed in #4 of the previous thread.... (you did pound a nail in you wife's favorite coffee table and try it didn't you???) That's the same thing! COM moves closer to the center of rotation at the nadir when angular velocity is maximum (swing rider stands up)... COM moves farther way from the center of rotation when the angular velocity is zero (when the swing reverses direction and the rider crouches back down) only in that case... a centripetal force is doing the work of moving the mass. I give mandrin an F for plagiarism and a C- for improper use of the term "centripetal". Case closed.
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Post by nmgolfer on Dec 17, 2011 0:37:14 GMT -5
PS seems el mandrino dela cesspool agrees with young mr. Finney in thinking douchebag a fitting name for me (and apparently you too Jeff). Do you think we ought to start refering to them as the two turd sandwiches? LOL... just kiddin! Lighten up madrino... lighten up mr. finney. You'll die young (and still wrong) taking this stuff so seriously.
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Post by natep on Dec 17, 2011 0:54:50 GMT -5
What you're saying makes sense to me. Looks like at least one forum member over there isnt buying it either. It will be interesting to see if he responds to anyone's objections.
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Post by gmbtempe on Dec 17, 2011 12:11:09 GMT -5
What you're saying makes sense to me. Looks like at least one forum member over there isnt buying it either. It will be interesting to see if he responds to anyone's objections. I kind of questioned it in as subtle way as possible, I dont want to do to much and get banned there.
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Post by nmgolfer on Dec 17, 2011 13:17:22 GMT -5
It will be interesting to see what turd sandwich two comes up with Were he honest he'd just post the link to the Wirkus Rand Ruina Cornell.edu paper and say that's where he got the answer. But it doesn't support his centripetal force doing work thesis. What moves the mass is leg muscles not the force in swing chains/ropes. PS I'll be watching assiduously. PSS Banning too many people too often (and reading their pm's) will kill a forum right quick. Seems most of the better discussion has migrated to Ritchies' excellent forum now. The cesspool's days may be numbered.
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