Question:
Calculate the amount of heat radiated per second by a body of surface area $12 \mathrm{~cm}^{2}$ kept in thermal equilibrium in a room at temperature $20^{\circ} \mathrm{C}$. The emissivity of the surface $=0.80$ and $\sigma=6.0 \times 10^{-8} W / m^{2}-K^{4}$
Solution:
