2. Air at one atmosphere and approximately 400K is flowing in a 3m inside diameter smooth tube at 8m/s. a) Estimate the heat transfer coefficient at the inside wall using an empirical equation. b) For the purpose of only this part of the question, assume that the wall temperature is 350K and the measured air temperature (i.e., average bulk temperature) is 398K at the axial position of ten meters (i.e., the temperature is lowered by 2K/10m of tube length). Calculate the heat transfer coefficient based on this data. The surface temperature of the heater is to be kept no higher than 425C. Determine the maximum allowable electrical power density (qW/m3) within the heater