The surface temperature of a hot plate is $175^{\circ} \mathrm{C}$. The ambient air temperature is 25 ${ }^{\circ} \mathrm{C}$. The rate of heat transfer per unit area in $\mathrm{kW} . \mathrm{m}^{-2}$ from the plate to the ambient air is _________ $\text{(Answer in integer)}$. Assume the convective heat transfer coefficient is $20 \mathrm{~W} \cdot \mathrm{m}^{-2} \cdot \mathrm{K}^{-1}$.
