(Solved): The apparatus sketched in the figure below serves as a viscometer i.e. it can be used to measure the ...

The apparatus sketched in the figure below serves as a viscometer i.e. it can be used to measure
the viscosity of a liquid. In the drawing, D is a large reservoir containing a viscous liquid A and
E is a cylindrical tube of radius R, open at both ends, surrounding and coaxial with B, which is a
cylindrical "bob" of radius ?R that is dragged up through the fluid by a frictionless pulley system
(C) utilizing a weight W. Determine a design equation that relates the viscosity of the liquid to
the geometry of the system and the weight W. Hint: you can assume that the length of the cylindrical tube is sufficiently long for the flow to reach steady state.