Re: Work/Energy theorem?

[David Bowman <dbowman@tiger.gtc.georgetown.ky.us>]

Leigh wrote:
> >       Yeah..... Sure you can tell the difference.  If "what you feel" is
> > too crude a measure for you, use an accelerometer.  My claim is that the
> > guy on the ground will see a reading of zero on his accelerometer, the guy
> > on the train will see his accelerometer read different from zero as the
> > train stops.
>
> John, Albert, and I will all be surprised by that result. I'm distinctly
> uncomfortable whenever my accelerometer reads zero!

I too would be surprised by that result.  However, it must be remembered that
this discomfort is not due to any physical effect.  It is a psychological
discomfort associated with the dread of an anticipated collision with the
upwardly accelerating ground.  The Columbia's (and Mir's) accelerometers are
now reading very close to zero (with any nonzero value being associated with
a tidal effect of the earth's gravitational field not being uniform over the
size of the craft, and the accelerometers not being located at exactly the
craft's center of gravity), and yet this does not result in the Columbia
crew having any sense of discomfort.  Rather, I'd expect that they are very
comfortable (after getting over any possible motion sickness related to
launch accelerations).

David Bowman
dbowman@gtc.georgetown.ky.us