A centrifugal pump is discharging water at the rate of 100 liters/s. The internal and external diameters of the impeller are 150 mm and 300 mm respectively. The width of the impeller at inlet and outlet are 12 mm and 6 mm. The vanes are curved bade at 45° to the tangent at outlet. Find the increase in pressure as the water passes through the impeller.