Average Force of Oxygen Molecule in Cubical Vessel

[cdotter]

Homework Statement

...Suppose an oxygen molecule (m=5.32E-26 kg) traveling at this speed ($\nu_{rms}=484 m/s$) bounces back and forth between opposite sides of a cubical vessel 0.10 m on a side. What is the average force the molecule exerts on one of the walls of the container? (Assume that the molecule's velocity is perpendicular to the two sides that it strikes.)

Homework Equations

$F=\frac{dp}{dt}$

The Attempt at a Solution

I can't remember how to do this, even after looking through my notes.

 

[cdotter]

Nevermind, I found it.

$$\frac{dP_x}{dt}=\frac{NAMv_x^2}{V}$$