Calculate the energy emitted by a grey surface of emissivity 0.45 at a temperature 800°C. The surface measures 5 m x 6 m. A small convex object of area A1, temperature T1and emissivity Elis enclosed...

Calculate the energy emitted by a grey surface of emissivity 0.45 at a temperature 800°C. The surface measures 5 m x 6 m.

A small convex object of area A1, temperature T1and emissivity Elis enclosed within a larger enclosure at temperature T2and emissivity E 2. Derive an expression for the net heat exchange between the two.