• Flat wall is exposed to an environmental temperature of 38◦C. The wall is covered with a layer of insulation 2.5 cm thick whose thermal conductivity is 1.4 W/m・ ◦C, and the temperature of the wall on the inside of the insulation is 315◦C. The wall loses heat to the environment by convection. Compute the value of the convection heat-transfer coefficient that must be maintained on the outer surface of the insulation to ensure that the outersurface temperature does not exceed 41◦C.