Chapter 5, Problem 5.66P

A long plastic rod of 30-mm diameter $\left(k=0.3\text{W/m}\cdot \text{K}\text{and}\rho c_p=1040{\text{kJ/m}}^{\text{3}}\cdot \text{K}\right)$ is uniformly heated in an oven as preparation for a pressing operation. For best results. the temperature in the rod should not be less than $200°\text{C}\text{.}$ To what uniform temperature should the md be heated in the oven if, for the worst case, the rod sits on a conveyor for 3 min While exposed to convection cooling with ambient air at $25º\text{C}$ and with a convection coefficient of $8{\text{W/m}}^{\text{2}}\cdot \text{K?}$ A further condition for good results is a maximum-minimum temperature difference of less than $10°\text{C}\text{.}$ Is this condition satisfied? If not, what could you do to satisfy it?