Re: Weight

[jmclean@chem.ucsd.edu (James Mclean)]

Richard W. Tarara says:
> Unlike many on the list, I have no problem with the concept of weight being
> a special name for the gravitational attraction of the earth (or other
> nearby, large astronomical body) on an object.   This gravitational
> attraction dominates our daily lives in a more direct way than the
> electrical force--we experience gravitational effects constantly while the
> (even more important) electrical ones are basically invisible to us--thus
> having a special name is not unwarranted.    OK, there is a practical
> problem with whether you call weight the net force towards the center of
> the earth or just the gravitational attraction but the effects of the
> rotating earth is usually not of major concern in an introductory course.
>
> I also have no problem with the 'weightless' astronauts--they're NOT.  They
> have no apparent weight but again I harken back to the fact that we
> experience our weight 'normally' through the balancing forces that keep us
> from accelerating.  In the absence of these 'upward' forces they _feel_
> weightless.  

It seems odd to me that you suggest using "weight" in a way that agrees
with every-day experience on Earth, but that once you are up on the space
shuttle you want to ignore simple experience.

I think the answer lies in the last sentence of your first paragraph.  On
earth, the apparent centrifugal force is negligible; nonetheless, it
technically should clearly be included in what we experience everyday as
"weight".  If is is also included on the space shuttle, then we find the
astronauts to be "weightless."

-- 
--James McLean
jmclean@chem.ucsd.edu
post doc
UC San Diego, Chemistry