Re: [Phys-l] buoyancy on a submerged pole

[brian whatcott <betwys1@sbcglobal.net>]

On 11/3/2010 9:33 AM, Chuck Britton wrote:
> 	(an off-list exchange - posted without permission - hope it's ok)
>
> At 10:14 AM -0400 11/3/10, bennett bennett wrote:
> > The way I see it,  the force of fluid pressure on solid is normal to
> > the surface at all points, so the anchored pole, (with no water
> > pushing on the bottom surface), is not lifted by the water on its
> > side, unless the water is viscous and moving upward.
> >
> > If there is a notch, the pressure on the non-vertical surfaces of
> > the notch will stretch only the thin part of the pole, but the up
> > and down forces will be equal, since the vertical components of the
> > forces on the surfaces of the notch are equal.
> And the way _*I*_ see it is that the top of the (totally) submerged
> pole doesn't give a flying-flip what's going on at the bottom of the
> pole.
> The top of the pole 'wants' to float, and it WILL if given a chance.
>
> How does the complicated contact force at the bottom change what's
> going on with the rest of the object??
> 	(Still scratching my head vigorously)
By affecting one of the several orthogonal  stresses which may exist in 
a material?   :-)

Brian W