A 14-in.-diameter circular plate is placed over a fixed bottom plate with a 0.1-in. gap between the two plates filled with glycerin as shown in the figure below. Determine the torque required to rotate the circular plate slowly at 3 rpm. Assume that the velocity distribution in the gap is linear and that the shear stress on the edge of the rotating plate is negligible. (Assume the viscosity of glycerin is 3.13 x 102 lbs/ft)