A hydraulic system operates at a gauge pressure of 20 MPa and 55°C. The hydraulic fluid is SAE 10W oil. A control valve consists of a piston 25 mm in diameter, fitted to a cylinder with a mean radial clearance of 0.005 mm. Determine the leakage flow rate if the gauge pressure on the low pressure side of the piston is 1.0 MPa. Piston is 15 mm long. The gap between the piston and cylindrical valve is very small, the flow can be modeled as a flow between parallel plates. Assume that the flow is laminar in nature and solve for Q. For SAE 10W oil at 55°C, - - 0.018 kg/m.s, SG=0.92. Calculate average velocity of the fluid.