Because the velocities of point A and point B are all along the tangent direction of the circle, we can get W=V/R by using the instantaneous center method, and O is the instantaneous center, so the velocity of the center of mass of AB is W* root sign 3R/2, and we can get the momentum. As for LO= root 3R/2*K+LC, the angular acceleration can be obtained by power equation, and then the principal vector and moment of inertia can be obtained. . .