$5-50.$ The $60-$ mm $-$diameter shaft is made of $6061.-T{h}_f$ aluminum having an allowable shear stress of ${}_{\text{a}\text{l}\text{l}\text{o}\text{w}}=80MPz$ Determine the maximum allowable torque $T.$ Also, find the corresponding angle of twist of disk A relative to disk $C.5-51.$ The $60-$mm$-$diameter shaft is made of $6061-$Th aluminum. If the allowable shear stress is ${}_{\text{a}\text{l}\text{l}\text{o}\text{w}}=80$MPa, and the angle of twist of disk A relative to disk $C$ is limited $s_0$ that it does not exceed $0\mathrm{.}06$ rad $,$ determine the maximum allowable torque $T.$

Probs. $5-50/51$