Mailing List Archive Mailing List Archive
--part1_49.7d7d2e4.27c89443_boundary Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Hi David, I'm sorry, but your theory doesn't hold water, so to speak. When we rate th= e=20 size of tanks, we rate them in terms of "Standard cuft." of gas. One=20 stdcuft. is one cuft. of gas at standard temperature and pressure (close to=20 room temperature and 14.7 psi. absolute.) For you to try to explain why the air filling a 104 cuft. tank weighs less=20 than the air filling an 80 cuft. tank, is kind of like your explaining how=20 you built a perpetual motion machine, how you solved the problems of world=20 poverty and how you cured all forms of cancer last week. It's going to be a= =20 real hard sell. Take care and dive safe, Scott Some weeks it's just not worth gnawing through the restraints and scrambling= =20 up out of the pit. In a message dated 2/23/2001 11:07:35 p.m. Hora est=E1ndar de EE.UU. O,=20 dthiesfeld@su*.ne* writes: >=20 > Rob, > No, and neither does the tank charts. >=20 > The tank charts are not telling you the physical weight of the air inside > them, only what the buoyancy characteristics are. When you start > pressurizing air in different sized fixed containers at different pressure= s > things do not remain linear. >=20 > Remember the 104 contains it air in a different sized container and at a > lower pressure than the 80 does. You have to look at Archimedes's Principa= l: > " Any object wholly or partly immersed in a fluid is buoyed up by a force > equal to the weight of the fluid displaced by the object." The key is how > much water the tank physically displaces because of its physical size and > weight, with and without the air. >=20 > A cubic ft. of air may weigh .08 lbs, but that's at atmospheric pressure > (sea level). You change the pressure (as in putting the air in a tank) and > the weight of that cubic ft. of air is going to change. The change is > governed by the physical size of the container and what the pressure is. >=20 > DT --part1_49.7d7d2e4.27c89443_boundary Content-Type: text/html; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable <HTML><FONT FACE=3Darial,helvetica><FONT SIZE=3D2>Hi David, <BR> <BR>I'm sorry, but your theory doesn't hold water, so to speak. When w= e rate the=20 <BR>size of tanks, we rate them in terms of "Standard cuft." of gas. O= ne=20 <BR>stdcuft. is one cuft. of gas at standard temperature and pressure (close= to=20 <BR>room temperature and 14.7 psi. absolute.) <BR> <BR>For you to try to explain why the air filling a 104 cuft. tank weighs le= ss=20 <BR>than the air filling an 80 cuft. tank, is kind of like your explaining h= ow=20 <BR>you built a perpetual motion machine, how you solved the problems of wor= ld=20 <BR>poverty and how you cured all forms of cancer last week. It's goin= g to be a=20 <BR>real hard sell. <BR> <BR>Take care and dive safe, Scott <BR> <BR>Some weeks it's just not worth gnawing through the restraints and scramb= ling=20 <BR>up out of the pit. <BR> <BR> <BR>In a message dated 2/23/2001 11:07:35 p.m. Hora est=E1ndar de EE.UU. O,=20 <BR>dthiesfeld@su*.ne* writes: <BR><BLOCKQUOTE TYPE=3DCITE style=3D"BORDER-LEFT: #0000ff 2px solid; MARGIN-= LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px"> <BR>Rob, <BR>No, and neither does the tank charts. <BR> <BR>The tank charts are not telling you the physical weight of the air insid= e <BR>them, only what the buoyancy characteristics are. When you start <BR>pressurizing air in different sized fixed containers at different pressu= res <BR>things do not remain linear. <BR> <BR>Remember the 104 contains it air in a different sized container and at a <BR>lower pressure than the 80 does. You have to look at Archimedes's Princi= pal: <BR>" Any object wholly or partly immersed in a fluid is buoyed up by a forc= e <BR>equal to the weight of the fluid displaced by the object." The key= is how <BR>much water the tank physically displaces because of its physical size an= d <BR>weight, with and without the air. <BR> <BR>A cubic ft. of air may weigh .08 lbs, but that's at atmospheric pressure <BR>(sea level). You change the pressure (as in putting the air in a tank) a= nd <BR>the weight of that cubic ft. of air is going to change. The change is <BR>governed by the physical size of the container and what the pressure is. <BR> <BR>DT</FONT></HTML> --part1_49.7d7d2e4.27c89443_boundary-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]