Question: A hot liquid (cp = 950 J/kg·K) flows at a flow rate of 0.005 kg/s inside a tube with a diameter of 25 mm. At the tube exit, the liquid temperature decreases by 8°C from its temperature at the inlet. The hot liquid causes the tube surface temperature to be 120°C. To prevent thermal burn hazards, the tube is enclosed with a concentric outer cover of 5 cm in diameter. Determine whether the outer cover temperature is below 45°C to prevent thermal burns in contact with human skin. Evaluate the properties of air in the concentric enclosure at 80°C and 1 atm pressure. Is this a good assumption?
