a$)$ Describe boundary layer, central frictionless cone and developing length in

context of entrance conditions for laminar flow.

b$)$ Water at $50C$ llows in a pipe of $30cm$ diameter with velocity $($v$)=4\frac{m}{sec}.$

Head loss measurements indicate that friction factor $(f=0\mathrm{.}022).$ Determine

shear stress at $10cm$ from the centerline and centerline velocity. Take

tithematic Viscosity as $0\mathrm{.}553{10}^{-6}\frac{m^2}{sec}.$