A parallel plate flow chamber is being designed to study the adhesion of leukocytes to endothelium. The channel width is 2cm; the viscosity of the tissue culture liquid medium is 0.0087 g/cm-s. Determine channel heights that can be used to generate wall shear stresses (i. e., ) as high as 20 dynes/cm^2 with flow rates less than 2 ml/s.