A thin uniform rectangular plate of mass $$2 \mathrm{~kg}$$ is placed in $$x y$$-plane as shown in figure. The moment of inertial about $$x$$-axis is $$I_x=0.2 \mathrm{~kgm}^2$$ and the moment of inertia about $$Y$$-axis is $$I_y=0.3 \mathrm{~kgm}^2$$. The radius of gyration of the plate about the axis passing through $$O$$ and perpendicular to the plane of the plate is

A particle is moving uniformly along a straight line as shown in the figure. During the motion of the particle from $$A$$ to $$B$$, the angular momentum of the particle about $$O$$