NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/sci/physics/21689

Text File | 1992-12-23 | 1.7 KB | 40 lines

Newsgroups: sci.physics
Path: sparky!uunet!spool.mu.edu!darwin.sura.net!gatech!destroyer!cs.ubc.ca!newsserver.sfu.ca!news
From: [e-mail] (Leigh Palmer)
Subject: Re: Christmas problem
Message-ID: <[e-mail]>
Sender: [e-mail]
Organization: Simon Fraser University
References: <[e-mail]> <[e-mail]>
Date: Wed, 23 Dec 1992 20:41:06 GMT
Lines: 28

In article <[e-mail]> [e-mail] (Maarten van Loon) writes:

>1. A glass of water is standing on a balance.
>   At a certain moment someone puts a thermometer in the glass,
>   without touching the glass and still holding the thermometer
>   in his (or her) hand. Question: does the balance show a
>   heigher or lower weight or does it indicate the same weight?

The weight measured by the balance will include the (transmitted) reaction
to the bouyant force on the thermometer, equal to the weight of the volume
of water displaced.

>2. An astronout takes a bottle filled half with whine with him
>   in space. What does he see when he looks to the bottle in
>   space?

I don't know what a half-filled bottle of wine would look like in space,
but if one drops a bottle it looks "sloshed" while in free fall. It's my
guess that "sloshed" is as good an answer as you will get. If the bottle
were to remain absolutely unperturbed the minimum energy condition would
be determined by surface tension, and the minimum surface condition
corresponds pretty much to the shape the liquid takes in a more mundane
environment. That is, ultimately an undisturbed half-full bottle of wine
would have the wine at one end or the other and a flat air-wine interface.

MX&aHNY,

Leigh