An object and a plane mirror are shown in figure. Mirror is moved with a velocity ‘v’ as shown. The velocity of the image is

 

In perpendicular direction of the mirror,

${\overrightarrow{\mathrm{V}}}_{\mathrm{I}}=2{\overrightarrow{\mathrm{V}}}_{\mathrm{M}}-{\overrightarrow{\mathrm{V}}}_{\mathrm{O}}=2{\overrightarrow{\mathrm{V}}}_{\mathrm{M}}$

$\left|{\overrightarrow{\mathrm{V}}}_{\mathrm{I}}\right|=2\mathrm{v} \mathrm{sin\theta }$

In horizontal direction, velocity of the image will be zero as the velocity of the object is zero.