A $2-$in$.$ diameter shaft is supported by two sleeves, each of length $=2$ in$.$ as shown. The internal diameter of the sleeves is $2\mathrm{.}1$ in$.$ The radial space between the shaft and the sleeves is filled with an oil of viscosity $=8$x$10-3$ lb$-$s$/$ft$2.$ If the shaft is rotated at a speed of $600$ rpm$,$ the viscous torque $($ft$-$lb$)$ on the shaft is most nearly