Asystem for heating water with an inlet temperature of 25°c to an exiting temperature of 70°c involves passing the water through a thick-walled tube with inner and outer diameters of 25 and 45 mm, respectively. the outer tube surface is well insulated, and the electrical heating within the tube wall provides for a uniform generation of q_ 1.5 106 w/m3. a. for a mass flow rate of water, m_ 0: 12 kg=s, how long must the tube be to achieve the desired outlet temperature? b. if the inner surface of the tube at the outlet is t s 110°c, what is the local convective coefficient at this location?