Physics

Problem

A cube of side

0.25\,\text{m}

is at

1000\,\text{K}

inside a vacuum chamber. Three mutually perpendicular faces are coated with paint of emissivity

0.8

, while the remaining three faces have emissivity

0.3

. Calculate the total energy radiated by the cube in

2.0\,\text{min}

. (Use

\sigma = 5.67 \times 10^{-8}\,\text{W}\,\text{m}^{-2}\,\text{K}^{-4}