A thin horizontal disc is rotating about a vertical axis passing through its fixed centre O . Its angular momentum is L_A and L_B computed about points A and B , respectively, with OB=2 OA . The value of L_A L_B is :

Step-by-step solution

The angular momentum of a rigid body about any arbitrary point P is given by the relation: L _P = L _ cm + r _ cm/P M v _ cm where L _ cm is the angular momentum of the body about its center of mass, r _ cm/P is the position vector of the center of mass with respect to point P , M is the total mass of the body, and v _ cm is the velocity of the center of mass. In the given problem, the disc is rotating about a vertical axis passing through its fixed center O . Since the center of mass of the disc is at O and is fix