(10 pts) The differential energy balance for a steady-state, open-system with onedimensional flow across the boundaries, a single inlet, a single outlet, and negligible variation of height, density, and enthalpy across either inlet or outlet area is gdz+vdv+dH=Q+Ws where Q and Ws denote inexact differentials (path dependent) of Q and Ws and the rest of the notation is consistent with the notation used in the lecture. Explain how to derive the differential mechanical energy balance given by: gdz+vdv+dp=WsWf where Wf is the frictional losses. Hint: define the frictional losses as the heat generated by friction as Wf=TdSQf where S denotes entropy (recall that heat lost by the fluid is negative). Make sure to justify this expression