>>>>Subject: Re: Inertia Dennis, Inertia is a function of mass and velocity. My system describes mass as strike weight and velocity as strike ratio in terms that are usable by piano makers and technicians. Hammers have evolved to an upper limit that is very well defined by the weight of Steinway concert grands and which correlate very closely with my "full" projection zone. Is there an argument with what is used on 90% or so of all performance pianos? David C. Stanwood>>>>> Inertia has nothing to do with velocity and for all practical purposes it is synonomous with mass. When you say that something is a function of something else you mean that it is dependent upon some variable. In this case you might want to refer to Rotational Inertia which has a rather complicated definition where the distribution of mass around a center and its distance from that center is summed up for an area or volume in question. >From Newtons Second Law we can get a definition of inertial mass. F = m * A where F is a force, m is the mass, and a is the acceleration. For example, Suppose I have a 50 lb. weight we can calculate the mass by 50 lb. = m * 32 ft/sec^2 Here the F or force is the weight and A is gravitional acclereration here on the face of the earth. Do a little algebra and you will have the mass. Michael Wathen
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