Problem$12-107$

Asmiface has an absorgtivity of ${}_s=0\mathrm{.}72$ for solar radiation and an emissivity of $=0\mathrm{.}6$ at room temperathre. The surfere thmperathre is observed to be $350$ K when the direct and the diffuse components of solar radiationare Go $=350$ and $Gr=400W{m}^2,$ respectively, and the direct radiation makes a $30$ angle with the nomal of the surfice. Taking the efiective sly trimperathre to be $280$ K $,$ determine the net rate of radiation heat transfer to the surface at fhat fime.