Two parallel plates kept $100$ mm apart have laminar flow of oil between themwith a maximum velocity of $1\mathrm{.}5$ m$/$s$.$ Take the viscosity of oil to be $24\mathrm{.}5$ Poiseand determine the following per unit length:$($a$)$ The discharge per metre width,$($b$)$ The shear stress at the plates,$($c$)$ The difference in pressure between two points $20$ m apart, and$($d$)$ The velocity at $20$ mm from the plate