[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PSUBS-MAILIST] Newbie

.....Boyle's law. Here's a rather cute animation..

http://www.grc.nasa.gov/WWW/K-12/airplane/aboyle.html

Joe

From:  "Paul Kreemer" <paulkreemer@gmail.com>
Reply-To:  personal_submersibles@psubs.org
To:  personal_submersibles@psubs.org
Subject:  Re: [PSUBS-MAILIST] Newbie
Date:  Fri, 11 May 2007 11:51:57 -0700

And if you can keep your air volume constant you won't have to change your ballast too much as you descend or ascend. 
 
The buoyancy from a submerged volume of air doesn't change, unless the density of the water and/or air changes.  Which happens.  Anyway, the lifting force of air in seawater should stay close to 64 lb/cubic foot, or 1025 kg/cubic meter.
 
Now if you were talking about a balloon filled with air, where the volume could change, then you'd see the behavior you suggest, except reversed.  As the balloon goes deeper, the water pressure will compress the air, and the lift will decrease.  A cubic meter of air at the surface would compress to half its volume (and lift) at a 10m depth.
 
Any fact checking on this would be good.  :-)
 

************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 53 Weare, NH 03281 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************