in a certain viscous (glycerine), incompressible flow field with zero body forces the velocity components are
u = ay - b(cy - y^2)
v = w = 0
where a, b, and c are constants. (a) Use the Navier-Stokes equations to determine an expression for the pressure gradient in the x direction, (b) For what combination of the constants a, b, and c (if any) will the shearing stress, r xyz, be zero at y = 0 where the velocity is zero?
