Liquid oxygen is stored in a thin-walled, spherical container 0.8 m in diameter, which is enclosed within a second thin-walled, spherical container 1.2 m in diameter. All surfaces are opaque, diffuse, and gray, and have a total hemispherical emissivity of 0.05. Both surfaces are separated by an evacuated space. If the outer surface is at 280 K and the inner surface is at 95 K, what is the mass rate of oxygen lost due to evaporation? Based on this mass rate of oxygen lost, how much is the liquid oxygen left in the container after 24 hours? The latent heat of vaporization of oxygen is 2.13 x 105 J/kg. The density of liquid oxygen at 95 K is around 500 kg/m3 . If the emissivity is increased to 0.9, do you think the evaporation rate will decrease or increase?