A non-equilibrium sample of gas in a cube has unequal mean squared velocity components such that ⟨vx2⟩=2⟨vy2⟩=2⟨vz2⟩. The number density and particle mass are uniform throughout the container. What is the ratio Px/Py of the pressure exerted on the wall perpendicular to the x-axis to that exerted on the wall perpendicular to the y-axis?
a) 1
b) 2
c) 2
d) 21