hammer velocity

[Richard Brekne]

Richard Moody wrote:

> YES!  The hammer as it strikes the string is actually slowing
> down in theory.    A major consideration of the design of the
> piano action is that the hammer must leave the  impelling device,
> (jack) and continue to travel for a tiny distance free and clear,
>  strike the string, rebound, and then come back in contact with
> the action mechanism which must now "catch" the hammer.

I believe there is a letoff position (just under 1mm) that is so close
that the hammer does not have a chance to start de-acceleration. I
havent gotten into all this side of things very much yet, so I am not
sure of myself here, but isnt there some sort of "left over" force that
keeps an object in acceleration for some small period of time even tho
the origional applied force is removed ?  Like a bullet coming out of a
rifle ?? Doesnt that meet its maximum acceleration some few milliseconds
after the explosion of the shell ?

>
>     The only aspect of the travel of the hammer the pianist can
> control is its velocity.  There might be an argument about this in
> physics because of the difference between velocity and
> acceleration.

I am sure you are right here.... (about the argument part) I have read
through 8 or 9 articles by those who have done the only readily
available real science on the subject matter and they dont draw any hard
conclusions. Most say that things seem to point in the direction you
mention, but the door seems held open and there are others who have
their foot through that door. The physchology of our perceptions gets
into play here as well, along with what is heard and coincidently felt.
Physics experiements have a hard time avoiding isolating too much in
order to afford an appropriate resolution for what they are trying to
look at, and in effect influence that which they are viewing. We must
never discount the reported experiences of the pianists in all this
either. The idea is to find the explaination as to why they experience
what they do.

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html