An incompressible fluid flows through a rectangular cross section duct, with width much larger than height of the cross section. The duct surface is heated at a uniform rate along its length. If the centreline of the flow is along the centre of the duct where v = 0, the distance from the centreline to the surface of the duct is b = 25 mm, and the thermal conductivity of the fluid is 0.6 W/mK, what is the local heat transfer coefficient in the developed region of the flow? Give your answer in W/mK to 1 decimal place.