PBL
What a very odd question!
Well, one measurement for pressure is PSI, another is pascals. I'm just wondering which one should be used
That depends on how much knowledge is worth to you.
True enough
Rusty? Would you care to be more precise?
I haven't used them in a long time...
selfin
The International Standard Atmosphere and the 1976 US Standard Atmosphere agree up to 32 kilometres. The latter standard is included in the references to the Wikipedia entry on ISA. Working with altitudes greater than this will require taking account of changes to R (gas constant for air). At sufficiently high Mach numbers account may need to be taken of changes to gamma.
Okay, so just to make sure I have all these variables right
q = dynamic air pressure
R = gas constant for air
rho = ambient air density
gamma = ratio of specific heat at a constant pressure to specific heat at a constant volume
The equations you'll need can be found in NACA Report 837.
I'll have to give it a look. I'm not particularly an expert on greek characters, so I'll have to find the greek-alphabet for that purpose.