(Solved): The figure below shows a light (massless) rod, with a ball of mass \( m \) attached to it at a dist ...

The figure below shows a light (massless) rod, with a ball of mass \( m \) attached to it at a distance \( d \) from the rotation axis marked with an \( \mathrm{x} \). The rod-ball object as shown has a rotational inertia of \( I \). If you add another ball of mass \( m \) at a distance \( 3 d \) from the axis of rotation on the other side what will be the new rotational inertia with both balls attached?