Water enters a circular tube with a flow rate of 0.012 kg/s and a uniform inlet temperature of 20 °c. the velocity profile is fully developed when the flow enters the tube, but the temperature profile is not. the tube, which has a length of 5 m and a diameter of 15 mm, has a fixed surface temperature of 40 °c. a) estimate the distance from the entrance at which the flow becomes fully developed thermally. b) determine the average convection coefficient on the inside surface of the pipe. c) determine the mean exit temperature. d) determine the heat transfer rate to the water.