Another way to look at it is that due to the barometer equation, the pressure on the bottom is higher than the pressure on the top so there's always an upward force.
Hoyt Stearns Scottsdale, Arizona US -----Original Message----- From: Michele Comitini [mailto:[email protected]] Sent: Thursday, June 16, 2011 6:43 AM To: [email protected] Subject: Re: [Vo]:Hot air rises, even in constant volume Air baloon float because of Archimedes' principle. Pressure inside the baloon balances external pressure + baloon surface elastic force any time. So if inner temperature is high enough air density inside is lower that air density outside. pV = nRT mic
