Hot air at 207 kPa and 200°C enters a 2.5-cm-ID tube at 6 m/s. The tube is constructed of copper with a thickness of 0.8 mm and a length of 3 m. Atmospheric air at 1 atm and 20°C flows normal to the outside of the tube with a free-stream velocity of 12 m/s. Calculate the air temperature at exit from the tube. What would be the exit hot air temperature when its flow rate is reduce to half without account for the change in inside heat transfer resistance? To simplify the above computation you may assume the inside heat transfer coefficient remains unchanged. What would be the exit temperature take into account the change in inside heat transfer resistance due to the flow rate change?