Consider a capillary completely filled with red blood cells $($RBCs$)$ as shown in the figure

below. We wish to derive an expression for the effective viscosity $($eff$)$ of the RBC

suspension passing through this capillary compared with that of plasma $($of viscosity $$p$)$

along passing through this capillary. You may assume that the small amount of fluid between

two adjacent RBCs moves at the same velocity as that of the RBCs$.$

$($a$)$ Let the velocity of each RBC be given a v$,$ and let the average pressure gradient $($

dP$/$dx$)$ driving the flow be G$.$ Can you find the velocity profile of the fluid in the gap

$(0$