A kind of viscometer is constructed with 2 concentric cylinders with fluid in between(see the figure below).If you have viscometer with two 30-cm-long cylinders ,one 20.0cm in diameter and the other 20.2cm in diameter,

1. A kind of viscometer is constructed with 2 concentric cylinders with fluid in between (see the figure below). If you have this viscometer with two 30cm-long cylinders, one 20.0cm in diameter and the other 20.2cm in diameter, a. How do you define shear stress? (2 pt) b. Use momentum balance, derived the equation for viscosity. Using the symbols in the following figure ( R : the radius for the inner cylinder, r : distance from center to somewhere between the two cylinders, h: distance between two cylinders, : the rotating velocity of the inner cyliner) ( 3pt) c. Calculate the viscosity of the tested fluid when a torque of 0.13N.m is required to rotate the inner cylinder at 400rpm. (3 pt) d. How big is the shear stress? (2 pt)