Problem $3$: Shear Stress $[15$ points$]$

Suppose a fluid with a viscosity of $$ flows between two flat plates due to a pressure gradient equal to dp$/$dx$.$ The velocity of this flow can be formulated as

$u=(\frac{H^2}{2})(-\frac{dp}{dx})(\frac{y}{H}(1-\frac{y}{H}))$

Find a formula for shear stress distribution within this flow.