Refrigerant flows in a copper tube of outer diameter of 4.8 cm. the inside surface temperature is -15 degree c and the room temperature is 20 degree c. the surface heat transfer coefficient between the tube and the room air is 25 w/m^2 middot k. ignore the thermal resistance of the copper tube, so that the outside wall temperature of the tube is the same as the inside wall temperature. 1) what is the heat gained by the refrigerant per unit length? 2) to reduce the heat gained from the room air, someone decided to put 4 mm of insulation (thermal conductivity 0.75 w/m middot k) around this tube. show that the heat loss per unit length actually increases after adding this insulation. 3) explain why you can expect the heat loss to increase.