7-50 An uninsulated steam pipe is used to transport high-temperature steam from one building to another.The pipe is of o.5-m diameter, has a surface temperature of 150°C, and is exposed

to ambient air at –10°C. The air moves in cross flow over the pipe with a velocity of 5m/s. (a) What is the rate of heat loss per unit length of pipe? C Consider the effect of insulating the pipe with(b)a rigid urethane foam (k = 0.026 W/m · K). Evaluate and plot the rate of heat loss as a function of the thickness 8 of the insulation layer for o s 8s 50 mm.