Consider a graphite sphere having a diameter of $30$ cm present at $60\backslash$deg C with an

emissivity of $0\mathrm{.}8.$ It is inserted into a container. The environment inside the container is

kept at $10\backslash$deg C and $0$ atm. Answer the following assuming a steady state.

A$)$ What is the mechanism of heat transfer? Why? $[10$ Pts$]$

B$)$ Estimate the heat transfer rate. $[15$ Pts$]$

C$)$ Estimate the heat energy transferred in $30$ seconds. $[15$ Pts$]$