Regarding the machine part in Question $2,$ calculate its total emissivity, $,$ at the time that it is placed into the furnace, when its temperature is a uniform TP $=300$K$.$ Over a period of time, the part will heat up$,$ eventually arriving at the temperature of the furnace walls and thereby attaining thermal equilibrium with the furnace. Calculate the equilibrium value of of the part at this time, as well.