Re: operational F, m, and a (velocity measurements with fish-scal es)

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

I have time to respond to only one aspect of John D's post:

I thought the velocity measurement was the least controversial of the points
I have been making; so I'll only address that point here.

> -----Original Message-----
> From: John S. Denker [mailto:jsd@MONMOUTH.COM]
> Sent: Thursday, October 18, 2001 3:50 PM
> To: PHYS-L@lists.nau.edu
> Subject: Re: operational F, m, and a

> > I gather, since you haven't objected yet,
> > that you agree that there is an
> > implicit (usually quite explicit) velocity measurement in
> the use of the
> > fish-scale.  Of course, a velocity measurement isn't an acceleration
> > measurement.
>
> I'm baffled here.  I don't see any relevant velocity
> measurement (or any
> relevant acceleration measurement).  Velocities and
> accelerations may exist
> as nuisances, but they are easily dealt with.

That makes two of us who are baffled :-)

I see a very relevant and necessary velocity measurement.

In order to use the fish scale, to make a reading or determination (e.g with
the one tick mark primary standard you developed  in another post) You must
first make a velocity measurement (determination) that the velocity of the
pointer relative to the tick marks is indeed zero. I don't think this is a
nuisance measurement, it seems to me that it is a required measurement and
therefore fundamental to the operation of such a device.

If I measure the velocity to not be zero (usually done visually and by
casual inspection, but *done none-the-less*); I don't take a reading.  I
wait until that measurement becomes zero, (this indicates that the scale has
settled down into equilibrium.  It strikes me that this is fundamental to an
equilibrium measurement; how else can I know that equilibrium has been
achieved without making this velocity measurement?).