rectangular enclosure measures $1\mathrm{.}5$ by $2\mathrm{.}0$ by $3\mathrm{.}0$ m$3.$ The top and bottom measure $1\mathrm{.}5$

by $2\mathrm{.}0$ m$2$ and are at $200$ K$.$ The two sides that measure $1\mathrm{.}5$ by $3\mathrm{.}0$ m$2$ are each at $250$ K$.$

The other two sides are at $200$ K and $300$ K$.$ Determine the net heat transfer rate from the

bottom surface. Treat all surfaces as blackbodies.