Problem on multistage centrifugal pump producing high head/ Fluid mechanics

How to draw velocity diagram for Centrifugal pump

A three stage centrifugal pump has impellers 40 cm in diameter and 2 cm wide at outlet. The vanes are curved back at the outlet at 45° and reduce the circumferential area by 10%. The manometer ice efficiency is 90 % and the overall efficiency is 80 %. Determine the head generated by the pump when running at 1000 rpm delivering 50 litres/s. What should be the shaft horse power?

Please support my channel, subscribe and share my videos with friends. My aim is to provide guidance related to concepts of engineering topics