Consider the flow of a fluid with viscosity μ through a circular pipe. The velocity profil...

Consider the flow of a fluid with viscosity μ through a circular pipe. The velocity profile in the pipe is given as u(r) = umax(l − rn/Rn), where umax is the maximum flow velocity, which occurs at the centerline; r is the radial distance from the centerline; and u(r) is the flow velocity at any position r. Develop a relation for the drag force exerted on the pipe wall by the fluid in the flow direction per unit length of the pipe.