Re: [Phys-l] Finishing up with that Dead Horse.

[Bernard Cleyet <bernardcleyet@redshift.com>]

That's why I prefer the bathroom scale definition.  Of course in teaching one must explain that the weight is due to more than just the presence of one big mass.

bc

p.s. IIRC the better gravitometers use a mass drop, which will be influenced by more than the presence of earth masses (plural to include mountains, etc.).    Horologists rate the quality of pendulum clocks by their ability to detect the presence of the moon.


On 2010, Nov 08, , at 16:03, carmelo@pacific.net.sg wrote:

> Quoting "Rauber, Joel" <Joel.Rauber@SDSTATE.EDU>:
>
> > It is a valid definition IMO, not my preference to define the weight  
> > as m*g where g is
> >
> > M*g = GMm/r^2 direction presumably pointing towards the center of a   
> > uniform spherical planet.
>
> Strictly, this is still not true.
> The direction of g is not towards the centre of a uniform spherical planet.
>
> Note that there is also gravitational force on the object from the  
> moon, Sun, etc...
>
> Some may even insist on including dark matter and dark energy. :-)