Question #$3$

$[5$ points$]$

To prove a point about how movies are wrong about outer space, Leonard runs an experiment. He microwaves an orange $(c_p=1\mathrm{.}8k\frac{J}{k}gC,$ mass $=0\mathrm{.}5kg,$ Diameter $=10cm)$ from a starting temperature of $20C$ to a final temperature of $80C$ and places it in the vacuum of outer space where it is allowed to radiate its heat away. If you assume the orange is perfectly spherical and will radiate heat as a blackbody, how long will it take for the orange to return to its starting temperature?