(b) Consider the fully developed flow of Citric acid (50% aqueous solution) at 50 C through a 60-m-long, 5-cm-diameter, horizontal, circular pipe. If the flow velocity at the centreline is measured to be 5 m/s, obtain the velocity profile and the pressure difference across this 60-m- long section of the pipe, and the useful pumping power required to maintain this flow. For the same useful pumping power input, determine the percent increase of the flow rate if the pipe is inclined 20 downward and the percent decrease if it is inclined 20 upward. The pump is located outside this pipe section. The density and dynamic viscosity of Citric acid at 50 C are 1220 kg/m and 0.3022 kg/m.s, respectively. 12 u(r) = Umax 1 R [15 marks]