Problem 1.307

Find the maximum power which can be transmitted by means of a steel shaft rotating about its axis with an angular velocity $\omega=120 \mathrm{rad} / \mathrm{s},$ if its length $l=200 \mathrm{~cm},$ radius $r=1.50 \mathrm{~cm},$ and the permissible torsion angle $\varphi=2.5^{\circ}$.