Two parallel plates $2m1m$ are spaced $1$ m apart. The plates are at temperatures of $727C$

and $227C$ and their emissivities are $0\mathrm{.}3$ and $0\mathrm{.}5$ respectively. The plates are located in a large

room, the walls of which are at $27C.$ Determine the rate of radiant heat loss from each plate and

the heat gain by the walls. $(5)$