We are interested in deriving the momentum balance for a pressure driven flow of an incompressible Newtonian fluid in a rectangular duct using the "shell balance" approach, see Figure 2. For a steady laminar flow, it may be reasonable to expect that the velocity components in the vertical and transverse directions are zero (i.e. vz=vy=0 ). Thus we may consider only the x-directional momentum balance about the control volume described in the figure. a.) What is the pressure force acting on the control volume? b.) Write down all non-zero components of the stress tensor, ? c.) For this flow it is easy to see that the "net rate of momentum transport by the flow" into the control volume is zero. Write down the x-directional momentum balance for the control volume using the results of (a)-(c) and letting x,y,z approach to zero. d.) What are the possible boundary conditions for this flow