The uniform arm OA has a mass of 4 kg, and the gear D has a mass of 5 kg with a radius o...

The uniform arm OA has a mass of 4 kg, and the gear D has a mass of 5 kg with a radius of gyration about its center of 64 mm. The large gear B is fixed and cannot rotate. If the arm and small gear are released from rest in the position shown in the vertical plane, calculate the initial angular acceleration α of OA.