Well my first post went into moderation, I suspect because I included the links for the locations of my source information and I’m sure they want to make sure I am not spamming or advertising or something nefarious. Perhaps I will take a different tack this time. No linking of reference material, so I guess you will just have to trust me.(adsbygoogle = window.adsbygoogle || []).push({});

I am trying to calculate the air pressure of an arbitrary point within a sphere filled with normal air. I had not imagined that straightforward calculations of air pressure would be so hard to find but it has been a beast, a well hidden beast.

I have the density of the atmosphere in the sphere and we can call the temperature 22 C or 295.15 K.

I found the below formula at a very secret and entirely undisclosed location -

D=P/R*T

D = density, kg/m3

P = pressure, Pascals ( multiply mb by 100 to get Pascals)

R = specific gas constant , J/(kg*degK) = 287.05 for dry air

T = temperature, deg K = deg C + 273.15

(101325 Pascals at sea level for earth)

And while it is a very pretty equation I am not trying to solve for density, I know the density via volume and mass. I want the pressure of a given point.

So I need to juggle the equation a little right? I need to make it

P=D*R*T

Is that right? I have no math brain for inverse properties.

Also

I should have mentioned earlier that this sphere filled with air has mass and thus gravity, so the air is not constant through-out but acted upon by gravity, denser toward the center and thinner toward the shell. But we can solve this by subtracting volume below us (relative to the center) from the total volume and recalculating density at our arbitrary point.

So my question is:

In order to make D=P/R*T solve for P is the new formula P=D*R*T?

If there is a better way to calculate air pressure at an arbitrary point as described above, I would love to know it

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# Air pressure calculation at an arbitrary point within a sphere

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