a) What is the importance of Reynolds number in pipe flow? b) Starting from a differential fluid element in a circular pump, show that the drop of pressure for a given length (1) is given by P P= = 32l D where, u is average velocity c) Oil of viscosity 9 poise (0.9NS/m) flows between two parallel fixed plates which are at a distance of 4 cm apart. If the drop of pressure in a length of 110 cm be 0.5 N/cm. Determine the rate of discharge of oil between the plates if width of plate is 25 cm. d) Water flows between two fixed parallel plates at a distance of 2 cm apart. The average velocity of flow is 0.35 m/s and the viscosity = 0.025 poise. Determine the maximum velocity, the pressure drop per unit length and the shear stress at the walls of the plates.