Consider a copper disc of diameter D $=50$mm and length L $=25$mm is heated to Ti $=$

$1000$K and cooled by an impinging air stream at T$\backslash$infty $=300$K and V $=4$ m$/$s$.$ The cooled

surface of the disk has an emissivity of $=0\mathrm{.}8$ and is exposed to large surroundings at

$300$K$.$ The remaining surfaces of the disk are well insulated, and heat transfer through the

thin supporting rod can be neglected.

Determine the heat transfer rate $($in W$)$ from the cooled surface.