$17-112.$

The circular concrete culvert rolls with an angular velocity of $=0\mathrm{.}5ra\frac{d}{s}$ when the man is at the position shown. At this instant the center of gravity of the culvert and the man is located at point $G,$ and the radius of gyration about $G$ is $k_G=3\mathrm{.}5$ ft$.$ Determine the angular acceleration of the culvert. The combined weight of the culvert and the man is $500lb.$ Assume that the culvert rolls without slipping, and the man does not move within the culvert.