Problem 3 The liquids described in Problem 2 are to be separated in a tubular centrifuge bowl with an inside diameter of 150 mm , rotating at 8,000 r/min . The free -liquid surface inside the bowl is 40 mm from the axis of rotation . If the centrifuge bowl is to contain equal volumes of the two liquids , what should be the radial distance from the rotational axis to the top of the overflow dam for the heavy liquid ? Problem 4 Water enters a 100-mm-ID 90 elbow, positioned in a horizontal plane, at a velocity of 6 m/s and a pressure of 70 kNo/m gauge . Neglecting friction , what are the magnitude and direction of the force that must be applied to the elbow to keep it in position without moving? Problem 5 A water tank is 30 ft in diameter, and the normal depth is 25 ft. The outlet is a 4-in horizontal pipe at the bottom (a) If this pipe is sheared off close to the tank , what is the initial flow rate of water from the tank ? (Neglect friction loss in the short stub of pipe .) (b) How long will it take for the tank to be empty ? (c) Calculate the average flow rate and compare it with the initial flow rate