Two plane mirror ${\mathrm{M}}_1$ and  ${\mathrm{M}}_2$ are joined about there edges and then this structure is moving with velocity $v_0$ as shown in the figure. A point object $\mathrm{P}$ is also moving with same speed $v_0$ in the direction shown in the figure. Determine the magnitude of the velocity of the image of $\mathrm{P}$ in ${\mathrm{M}}_1$ wrt image of $\mathrm{P}$ in ${\mathrm{M}}_2$?