<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; = charset=us-ascii"> <META NAME="Generator" CONTENT="MS Exchange Server version = 6.5.7036.0"> <TITLE>RE: Inertia</TITLE> </HEAD> <BODY>  This has been an = interesting thread. On the one hand we have = Don Gilmore who says the following: "Inertia is not an inherrent, quantifiable = property of an object, it's an effect, like the Doppler effect.  = There are no units of "inertia"; one object cannot have more = "inertia" than another.  It can have more kinetic energy, = or momentum, or mass, or velocity, or indeed "moment" of = inertia than another object since those are measurable, quantifiable = properties." Then we have Jim E. who = states:  "Inertia is directly related to mass.  A = lead ball the size of a ping-pong ball certainly has a lot more inertia = than the ping-pong ball because it has a lot more = mass." We are talking right = past each other. I'm with Ric. We need some clarity. Oh what the hell, = I'll try. The lead ping pong ball = does not in fact have more inertia than the regular ping pong ball. = However, it does take more force to change its direction +/or speed, = i.e. its velocity. It takes more force because it is more massive, not = because it has more inertia. Inertia is "the tendency" of a = body (an object) to resist a change in its velocity (at rest, that = velocity is zero). A more massive object doesn't "have" more = inertia, it has more mass. Ed Sutton is really = trying to steer us in a more fruitful direction when he = says: But = what we are trying to do here (I think?), is try to make piano actions = better for the pianists. Since = there are so many kinds of pianists, there might be many ways to make = pianos better, of more adapted to various players and ways of = playing. And in = particular, we were concerned with the placement of key leads.  For = a long time many of us have followed the rule of thumb that it was = better to produce a given front weight by placing a large quantity of = lead close to the balance rail than by placing a smaller quantity close = to the front, that this makes the action "feel better" and = repeat faster, at least in the bass octaves. If = this is true, then it is worth going to a lot of trouble to do it, if = not, it is a waste of time. FWIW, Alan ____________________________________________= Alan McCoy, = RPT Eastern = Washington University 509-359-4627 amccoy@mail.ewu.edu </BODY> </HTML>