$(3-80)($see schematic$)$ A counter$-$shaft carrying two V$-$belt pulleys is shown in the figure. Pulley A receives power from a motor through a belt with the belt tensions shown. The power is transmitted through the shaft and delivered to the belt on pulley B$.$ Assume the belt tension on the loose side at B is $15$ percent of the tension on the tight side.

$($a$)$ Determine the tensions in the belt on pulley B$,$ assuming the shaft is running at a constant speed.

$($b$)$ Find the magnitudes of the bearing reaction forces, assuming the bearings act as simple supports.

$($c$)$ Draw shear$-$force and bending$-$moment diagrams for the shaft. If needed, make one set for the horizontal plane and another set for the vertical plane.

$($d$)$ At the point of maximum bending moment, determine the bending stress and the torsional shear stress.

$($e$)$ At the point of maximum bending moment, determine the principal stresses and the maximum shear stress.