The shaft is hollow from $A$ to $B$ and solid from $B$ to $C.$ The shaft has an outer diameter of $76$ mm $,$ and the thickness of the wall of the hollow segment is $10$ mm $.$

$($Figure $1)$

Part A

Determine the maximum shear stress developed in the shaft.

Express your answer to three significant figures and include the appropriate units.

${}_{\text{m}\text{a}\text{x}}=$

$$

Solve completely