Consider a fluid of constant (density , viscosity ) between two concentric cylinders (see figure below). There is no axial motion or end effect (vz = 0). Let the inner cylinder rotate at angular velocity i. Let the outer cylinder be fixed. There is circular symmetry, so the velocity does not vary with  and varies only with r. Determine the shell for this system, momentum balance on the shell and develop velocity distribution v as a function of r.