Estimate the average temperature that a planet would have if it has no atmosphere and albedo has an of $40\%($ Solar Constant $=1366$W$/$M$2,$ Radius of the Planet $=6\mathrm{.}38$x$10^5$m$,$ Stefan $-$Boltzmann Constant $=5\mathrm{.}67$x$10^-8$Js$^-1$m$^-2$K$^-4)$ Radiation Laws

Stefan$-$Boltzmann Law: Each black body object emits

radiation according to the $4$ th power of its temperature.

Unit area emission

$=5\mathrm{.}67{10}^{-5}J{s}^{-1}{m}^{-2}{K}^{-4}E=T^4$

Wien's Law: Wavelenght corresponding to the emitted

maximum energy is inversely proportional with the

temperature.

${}_{\text{m}\text{a}\text{x}}=\frac{b}{T}$