The total translational kinetic energy of a gas is given by
[tex]K= \frac{3}{2} PV [/tex] (1)
where this equation is derived from the ideal gas law, and where P is the gas pressure and V its volume.
For the gas in our problem, the pressure is
[tex]P=1.0 atm = 1.01 \cdot 10^5 Pa[/tex]
while the volume is
[tex]V=7.00 m \cdot 12.00 m \cdot 4.00 m =336 m^3[/tex]
Therefore, the total translational kinetic energy of the gas is (by using eq.(1))
[tex]K= \frac{3}{2}(1.01 \cdot 10^5 Pa)(336 m^3)=5.09 \cdot 10^7 J [/tex]
