A point object 'O' is at the center of curvature of a concave mirror. The mirror starts to move at a speed u, iin a direction perpendicular to the principal axis. Then, the initial velocity of the image is

Options

A. 2u, in the direction opposite to theat of mirror's velocity
B. 2u, in the direction same as that of mirror's velocity
C. zero
D. u, in the direction same as that of mirror's velocity

Answer

b.

Explanation

Image velocoti(w.r.t mirro) `=-mxx` object belocity (w.r.t. mirror)
Here `m=1`