A belt moves upward at velocity V, dragging a film of viscous liquid of thickness h, as in Fig. C4.2. Near the belt, the film moves upward due to no-slip. At its outer edge, the film moves downward due to gravity. Assuming that the only non-zero velocity is v(x), with zero shear stress at the outer film edge, derive a formula for (a) v(x); (b) the average velocity Vavg in the film; and (c) the wall velocity Vc for which there is no net flow either up or down. y,v h = const X, U ρ, μ 54 BELT