Consider a thin-walled, metallic tube of length L = 1 m and inside diameter Di = 3 mm. Water enters the tube at m = 0.015 kg/s and Tm.i = 97°C.

(a) What is the outlet temperature of the water if the tube surface temperature is maintained at 27°C?

(b) If a 0.5-mm-thick layer of insulation of k = 0.05 W/m ∙ K is applied to the tube and its outer surface is maintained at 27°C, what is the outlet temperature of the water?

(c) If the outer surface of the insulation is no longer maintained at 27°C but is allowed to exchange heat by free convection with ambient air at 27°C, what is the outlet temperature of the water? The free convection heat transfer coefficient is 5 W/m2 ∙ K.