The ?no-slip? condition means that a fluid sticks to a solid surface. This is true for both fixed and moving surfaces. Let two layers of fluid be dragged along by the motion of an upper plate as shown in the figure below. The bottom plate is stationary. The top fluid puts a shear stress on the upper plate, and the lower fluid puts a shear stress on the bottom plate. The velocity profiles of both fluids are linear. Determine the ratio of these two shear stresses.

Fluid 1 Fluid 2 0.02 m 0.02 m 3 m/s 2 m/s = 0.4 N s/m = 0.2 N s/m U