$!$

Required Information

The ship at A has just started to drill for oll on the ocean floor at a depth of $h=5600ft.$ Knowing that the top of the $8-$In$.$diameter steel drill pipe $(G=11\mathrm{.}4\frac{{10}^6}{p}SI)$ rotates through $1\mathrm{.}8$ revolutions before the drill bit at $B$ starts to operate, determine the maximum shearing stress caused in the pipe by torsion.

The angle of twist, of end A relative to end $B,$ before $AB$ starts rotating as a rigid body is given as $=$

$($rad$)$