Re: shower physics

[Julie Hilsenteger <julie_hilsenteger@CENTENNIAL.K12.OR.US>]

A physics professor at the University of Mass. was just awarded an Ig Nobel
for doing actual research on this.
See:  www.improbable.com/ig/ig-pastwinners.html


Joe Heafner <heafnerj@VNET.NET> said:

> Hi.
>
> This may be an interesting problem. Every morning when I take a shower, I
notice that my rather thin vinyl shower curtain puffs towards the inside of
the shower as hot water comes out of the shower head. It never puffs towards
the outside of the shower. I've noticed this many times over the years and
have never been able to explain it. This morning, though, I observed
something very strange. I turned on the hot water and turned around to get
something. I peeked inside the shower and the curtain was flat! It didn't
start to puff out until I actually got into the shower! I had never noticed
this before.
> My usual, and probably wrong, explanation for the puffing was that the
warmed air inside the shower rises and a small convection effect caused the
shower curtain to puff out in the direction of the slightly smaller air
pressure, Bernoulli effect. But as the hot water continues to run, the entire
room warms up and this Bernoulli effect should decrease or even stop
completely. That is unless the running water continues to jostle the air
molecules around inside the shower. I had also considered an explanation
involving electric forces. Perhaps the curtain gains a charge from the
running water (but not much of the water actually hits the curtain and the
puffing is greater at the bottom than at the top so the charge would somehow
have to accumulate at the bottom of the curtain). Alternatively, maybe *I*
acquired a charge overnight (from cotton sheets?) and that small excess
charge is attracting the curtain to me! Well, this morning I noticed no
change in the amount of puffing of the curtain as I got closer and f
> Any ideas?
>
>
> Cheers,
> Joe
>
> CVAC Home Page <http://users.vnet.net/heafnerj/cvac.html>
> My Book <http://www.willbell.com/new/fundephcomp.htm>
> My Home Page <http://users.vnet.net/heafnerj/>
> Please -- no Microsoft attachments. They're a security risk.



--
Julie Hilsenteger
Physics Teacher
Centennial High School
3505 SE 182nd
Gresham, OR  97030
503-661-7612
julie_hilsenteger@centennial.k12.or.us