- #1
roam
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Homework Statement
http://img51.imageshack.us/img51/9484/therm.jpg
The Attempt at a Solution
My main problem is with the second part of the question. Here's my attempt at the first part:
[itex]p = \rho RT \implies \rho = \frac{p}{RT} = \frac{1010 \times 10^2 \ Pa}{287 \times 300.15 K}[/itex]
[itex]\therefore p = 1.1724 \ Pa[/itex]
(R was the specific gas constant for dry air = 287)
And for the second part:
If air is modeled as an ideal gas the only internal energy is kinetic and we can use:
[itex]K = \frac{3}{2} n R T[/itex]
(where R is the universal gas constant = 8.314)
But how do we find the number of moles for dry air? We must use the equation n=m/M. Here M is the molar mass (atomic number). But air is not a single gas, it is composed of several different gases. So how do we know its molar mass?? Do we have to use the atomic number of oxygen or nitrogen or carbon?
I appreciate any advice. If I've gone wrong anywhere else I would appreciate if somebody let's me know.
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