Physics

Problem

A planet orbits its star where the incident stellar flux is

900\,\text{W}\,\text{m}^{-2}

. The planet’s albedo is

0.25

and its infrared emissivity is

0.90

. In addition, geothermal processes deliver a uniform heat flux of

0.10\,\text{W}\,\text{m}^{-2}

at the surface. Neglecting any atmospheric effects, what is the planet’s equilibrium surface temperature? (Stefan–Boltzmann constant

\sigma = 5.67\times10^{-8}\,\text{W}\,\text{m}^{-2}\,\text{K}^{-4}

) a)

257\,\text{K}

227\,\text{K}

240\,\text{K}

182\,\text{K}