Re: [Phys-L] Nice question on buoyancy and balance

["Anthony Lapinski" <Anthony_Lapinski@pds.org>]

Spheres have same volume, so same amount of water displaced.

Imagine placing your finger in a beaker of water on a scale, but don't
touch the bottom of the beaker.
What will happen to the scale reading?

Why?



Phys-L@Phys-L.org writes:
> And from this you conclude...?
>
>
> On Wed, Jan 29, 2014 at 7:55 AM, Anthony Lapinski
> <Anthony_Lapinski@pds.org>wrote:
>
> > Simplify with fluids. The weight of the water displaced depends
> > on the volume of the submerged object.
> >
> >
> > Phys-L@Phys-L.org writes:
> > > My first thoughts are that the ping-pong side rises.  I look at the
> forces
> > > acting on the bottom of the pan.  Both sides have pressure from the
> water
> > > but since it's same area and depth, those terms are equal.  But on the
> > > left, there is a rope pulling up on the pan.
> > >
> > > On the other hand, if the ping pong ball had been held in place from
> above
> > > by a rigid dowel, say, then I'd guess that the pans would still
> balance.
> > > But since this is a buoyancy puzzle, I am prepared to be wrong...
> > >
> > >
> > > On Wed, Jan 29, 2014 at 4:36 AM, Savinainen Antti <
> > > antti.savinainen@kuopio.fi> wrote:
> > >
> > > > Hi,
> > > >
> > > > a former studen of mine send me a link to a nice question:
> > > > <http://wealthmanagement.com/question/puzzler-odd-balance>.
> > > >
> > > > I usually ask a variation of this question in my class. It is, in my
> > > > opinion, a good example of conceptual reasoning which goes well
> beyond
> > > rote
> > > > memorization. Probably many of you have seen this question before
> but I
> > > > thought it might be worth sharing.
> > > >
> > > > Regards,
> > > >
> > > > Antti
> > > >
> > > > --
> >
> > *************************************************************************
> > > > Viesti on tarkastettu roskapostinsuodatus- ja
> > > virustorjuntaohjelmistolla.
> > > >
> >
> > *************************************************************************
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