Question

Select One Correct Option from the following:Two thin circular discs of mass m 4m, having radii of a and$2 \alpha$, respectively, rigidly fixed by a massless, rigid rod of length $l=\sqrt{24} \alpha$ through their centers. This bly is laid on a firm and flat surface, and rolling without slipping on the surface so the angular speed about the axis of the rod is $\omega$ The angular of the entire assembly about the point ‘O’ is $\vec{L }$ (see the figure). Which the following statement(s) is(are) true?
(A) The center of mass of the assembly rotates about the z-axis with angular speed $\omega/5$.
(B) The magnitude of angular momentum of center of mass of the about the point O is $81ma^2\omega$.
(C) The magnitude of angular momentum of the assembly about its of mass is $17ma^{2} \omega/2$.
(D) The magnitude of the z-component of $\vec{L }$ is $55ma^{2} \omega$.

Answer 1

a option is correct I think

Answer 2

✔️(A) The center of mass of the assembly rotates about the z-axis with angular speed $\omega/5$.