What is the thermal energy of the gas?

[fadooda]

Homework Statement

A 6.0-cm-diameter cylinder of nitrogen gas has a 4.0-cm-thick movable copper piston. The cylinder is oriented vertically,
and the air above the piston is evacuated. When the gas temperature is 20 deg C, the piston floats 20 cm above the bottom of the cylinder.
-If the rms molecular speed is 550 m/s, what is the thermal energy of the gas?

P was figured to be 3500 Pa

 

[Redbelly98]

Welcome to PF

We generally like to see the sections from the homework template filled in. For example, what equation is there that deals with the thermal energy of a diatomic gas such as nitrogen?