Consider the conditions of Problem 3.149, but now allow for a tube wall thickness of 5 mm (inner and outer diameters of 50 and 60 mm), a fin-to-tube thermal contact resistance of 10- 4 m2 ∙ K/W, and the fact that it is the water temperature, T w = 350 K, rather than the tube surface temperature, that is known. The water-side convection coefficient is hw = 2000 W/m2 ∙ K. Determine the rate of heat transfer per unit tube length (W/m) to the water. What would be the separate effect of each of the following design changes on the heat rate: (i) elimination of the contact resistance; (ii) increasing the number of fins from four to eight; and (iii) changing the tube wall and fin material from copper to AISI 304 stainless steel (k = 20 W/m ∙ K)?