Re: Weight

["Rauber, Joel Phys" <RAUBERJ@mg.sdstate.edu>]

> > I too define weight in this fashion, although for simpler reasons than
> > talking about non-inertial frames, and free-fall frames etc.
>
> > Simply put, if you define weight to be the gravitational force acting on 
an
> > object; how do you explain why we say astronoughts are weigtless while
> > orbiting the earth, since they still have a gravitational force acting on
> > them.
>
> > Therefore defining weight as the magnitude of the non-gravitational force
> > present balancing the gravitational force on the scale used, relieves one
> > from the above conundrum and allows one to consistantly understand the 
term
> > weightless up on the space-shuttle
>
> Joel

> A good point, but since this definition depends on the vertical component
> of acceleration, maybe we should dispense with the use of the word "weight"
> from our explanations entirely.  I would hate to tell a student swinging a
> bucket in a vertical circle that the "weight" of the bucket was varying in
> magnitude and alternately up then down.  I'd rather talk about the tension
> in the rope.

Interesting example, in this case I too, would rather talk about tension, 
but I also think I wouldn't mention the idea of weight here either.  I'd 
restrict the conversation to tension and force of gravity.

> Likewise rather than calling the normal force holding you up your "weight",
> maybe we should just call it the normal force.

There are normal forces that don't hold up some entities weight.  E.G. the 
classic problem of and accelerating block pushing another from their sides. 
 And one is asked what the acceleration must be to keep the other one 
suspended and not sliding down (Do not neglect friction)

Joel