Physics - Fluid Question with Solution | TestHub

Water is flowing on a horizontal fixed surface, such that its flow velocity varies with y (vertical direction) as v $=\mathrm{k}\left(\frac{2{\mathrm{y}}^2}{{\mathrm{a}}^2}-\frac{{\mathrm{y}}^3}{{\mathrm{a}}^3}\right)$. If coefficient of viscosity for water is $\eta$, what will be shear stress between layers of water at $\mathrm{y}=\mathrm{a}$.