Problem #4: Average Velocity for Mass Balance in Turbulent Flow | For turbulent flow in a smooth, circular tube with a radius R, the velocity profile varies according to the following expression at a Reynolds number of about 10%. R-r R Equation 4.2-20 Where r is the radial distance from the center and is the maximum velocity at the center. (a) Sketch the system, define your coordinates and origin point. (b) Derive the equation relating the average bulk velocity with the maximum velocity for an incompressible fluid.