Water flows into a two-dimensional (2D) diffuser having an expansion angle of 20. It can be assumed that the flow in the diffuser can be approximated as a radial potential flow emanating from a source to the origin 0 as indicated in the figure Paroi du diffuseur 20 coulement entre sortie a) If the inlet velocity is 20 m/s, determine an expression for the pressure gradient, dp/dr along the diffuser wall. b) What is the pressure difference between the inlet and outlet?