The viscosity of a fluid is to be measured by a viscometer constructed of two 50-cm-long concentric cylinders. The outer diameter of the inner cylinder is 20 cm, and the gap between the two cylinders is 0.10 cm. The inner cylinder is rotated at 300 rpm, and the torque is measured to be 6.0 N-m. Calculate the viscosity of the fluid. ( B ) A capillary tube of 1.0 mm inner diameter is dipped in a beaker containing mercury at a temperature of 20°C. Solve the height of mercury in the tube if it stands in a vertical position. Hint: (1) the contact angle for mercury, F = 140°. (2) the surface tension for mercury, 0.440 N/m.