<html> <blockquote type=cite cite> <br> As for the force discussion, Newton's second law has the resultant equation the F=ma. Which is force equals the mass times the acceleration. Disregarding friction, the forces input into a linkage system will equal the forces produced by a linkage system. This means F[at the key] = F[at the hammer] = F[at the string]. Going further, if we subsitute the mass x the acceleration (ma)side of the equation, then ma[force at key] = ma [impact of hammer] = ma[string vibration].</blockquote><br> <br> <br> Hi Tom,<br>            There is a lot more energy loss, other than friction. Bending of the various components, key, jack, hammershank etc. The hammer absorbs a greater amount as the shoulders flex. ( combined with friction, action saturation)<br> Hard hammers tend to produce a very strong fundamental, (mid section upwards) with small partial development, therefore it will produce a wider string excussion on a repeated blow. This will increase fatigue, and hence breakage.<br> The point is that, a very significant proportion of the energy is dissipated within the action and hammer.<br> To find the actual energy that the string is producing, you need to know the sum of the RMS value of all the partials.<br> The louder that you play the instrument, the less efficient it becomes as you approach saturation.<br> Regards Roger<br> <div>Roger Jolly</div> <div>Saskatoon, Canada.</div> <div>306-665-0213</div> Fax 652-0505 </html>