|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
Sorry, the freezing caused permanent damage.
TEd
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
> the fact that brass is normally impervious to freezing...
[hair splitting post] It's brass's coefficient of thermal expansion that's at the root of all this. Its freezing point is around 875 degrees C. [/hair splitting post]
stales
|
|
|
|
|
Joined: Jun 2001
Posts: 2,636
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jun 2001
Posts: 2,636 |
875 degrees C
Is it just me, or is it really hot in here?
|
|
|
|
|
Joined: Oct 2000
Posts: 5,400
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Oct 2000
Posts: 5,400 |
no-- that sound right.. remember, "freezing" is going from a liquid state to a solid state. Water does it at 32 F., or 0 c.--- i don't think i have ever seen liquid brass, and even when soldering, a lead solder is used--
what we are concerned with, is some materials, even after they have become solid, expand and contract. steel does it noticable.. since it is very elastic for a metal.. and bridges are "higher" in the winter than they are in the summer.. and bridges all have expansion joints... even little 50 foot long highway overpass bridges..
what i think is being discussed, is brass does not expand or contract in a normal range of tempuatures.. say from -10 C. to 150 C. -- (though normal could be defined in other ways, but from sub zero to 20 lbs of steam is a pretty wide range.. yet one we might encounter in our daily lives (a very cold freezer, to a pressure cooker, or steam radiator.) but a metal lid to a jar will get a bit looser if you hold it under hot tap water...
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
Check this site: http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicslectures/ch8coefficientexpansion.htmlNote: Brass's coefficient of expansion is 19.3 X 10^-6 and iron's 12.1 X 10^-6. This means that an iron cannonball that is 4" at 10°C is going to measure 3.999032" at -10°C. If it is in a 3" brass hole, that hole will shrink from 3" at 10°C to 2.998842" at -10°C . This is close enough to not shrinking for me.
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
Enough about brassholes and the expansion and shrinking thereof.
|
|
|
|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
Of course if a 4 inch cannonball is in a 3 inch brass hole it is going to be VERY tight.
TEd
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
very tight
No. It would just sit up a little bit. You're not trying to put the cannonball through the hole. This is how I interpreted the original telling of the brass monkey story. You've got a brass plate with holes big enough for the cannonballs to sit in to keep them from rolling around the deck. Somehow the coefficient of expansion was supposed to make the holes too small (or is it too large?) to adequately prevent the balls from rolling out.
|
|
|
|
Forums16
Topics13,913
Posts229,412
Members9,182
| |
Most Online3,341
Dec 9th, 2011
|
|
|
0 members (),
953
guests, and
2
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
