1. A furnace wall 25 cm thick has a mean thermal conductivity of 1.384 W/m.K. Its inside wall temperature is 1400 deg C. The other side of the wall is exposed to air whose bulk temperature is 45 deg C. The heat transfer coefficient for the boundary layer between the outer wall and bulk air is given by the expression: (h=8.05 +0.087 DT), where DT is the gradient between the outer wall and the bulk air. What is the rate of heat loss per unit area? (Note: This requires assuming the unknown temperature)