David Love wrote: > It seems to me that because everything resists being moved (inertia) that > acceleration probably takes place through the entire key stroke. I would > guess that the first mm of movement doesn't achieve much for the reasons > that have been discussed, namely the flexing, compacting of various parts. > > David Love > davidlovepianos@earthlink.net > We were talking about the acceleration of the key itself David, the actions compliance as a whole is a seperate issue, albiet a good one. Of course acceleration / or deacceleration occurs through the whole key stroke, (except perhaps very rarely... what a steady touch tho eh ?). But the presence of acceleration does not simply eliminate the affect of any momentum, and that seems to be what is being said. The applet I sent a link clearly showed that all other things being equal, a given mass halfway along the key would accelerate faster then half that amount out at the end for the same downward force. I put 100 grams on the "rope" as it were, and 250 on the left side edge of the "platform". Then ran the applet first with 250 grams at the right side edge of the platform, and then 500 grams half way in on the right side. This resulted in a faster acceleration for the 500 gram configuration. The 100 grams pulling at the rope is the input force here, and the "platform" is the key. Only significant detail missing relative to the inertia question isolated from all the other stuff thats being mixed in, is the orientation of gravity here, as the "platform" rotates horizontaly. That however, just takes gravity out (more or less) of the picture in the demonstration. Its all part of a link to an online physics resource. Good for clowns, Steinway enthusiasts, and Wissner lovers everywhere :) Cheers RicB I'm off for a weekend of camping. See you all on monday ! RicB -- Richard Brekne RPT, N.P.T.F. UiB, Bergen, Norway mailto:rbrekne@broadpark.no http://home.broadpark.no/~rbrekne/ricmain.html
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