A very thin and long pipeline, used for the transport of crude oil, is buried in the earth such that its centerline is a distance of 1.5 m below the surface. The pipe has an outer diameter of 0.5 m and is insulated with a layer of cellular glass 100 mm thick. What is the heat loss per unit length of pipe under conditions for which heated oil at 120°C flows through the pipe and the surface of the earth is at a temperature of 0°C? What is the temperature at the outer surface of the cellular glass insulation? Draw schematically the isotherms inside the soil and the heat flux plot. Assume that thermal resistance due to convection in the oil is neglected, and temperature is uniform on the surfaces of the pipe and glass fiber.