Consider fully developed flow between parallel plates with the upper plate moving at \(U=5 \mathrm{ft} / \mathrm{s}\). The spacing between the plates is \(a=0.1 \mathrm{in}\). Determine the flow rate per unit depth for the case of zero pressure gradient. If the fluid is air, evaluate the shear stress on the lower plate and plot the shear stress distribution across the channel for the zero pressure gradient case. Will the flow rate increase or decrease if the pressure gradient is adverse? Determine the pressure gradient that will give zero shear stress at \(y=0.25 a\). Plot the shear stress distribution across the channel for the latter case.