A centrifugal pump is used to deliver water. The impeller has inner radius of 25 mm, outer radius of 70 mm, inner width 10 mm, outer width 5 mm and rotates at 1300 rpm. The blade angles at inlet and outlet are 45 and 30 respectively. (a) With the aid of a velocity diagram, determine the pressure rise across the impeller using the Bernoulli equation in rotating coordinates given in Egn 1 below. Assume ideal, no pre-rotation and no change in potential energy. P + Z + pg 2g - P2 +22 Pg + v- u?? 2g Eqn 1 Then, find the new pressure rise across the impeller if there is pre-rotation such that the tangential velocity at the inlet is about 30% of the inlet peripheral speed