If an observer is walking away from a plane mirror with a velocity of $6\;m/s$,then the velocity of the image with respect to the observer will be........$m/s$.

$A$ point source of light $S$,placed at a distance $60 \,cm$ in front of the centre of a plane mirror of width $50 \,cm$,hangs vertically on a wall. $A$ man walks in front of the mirror along a line parallel to the mirror at a distance $1.2 \,m$ from it (see in the figure). The distance between the extreme points where he can see the image of the light source in the mirror is $\ldots \ldots \ldots \,cm.$

$A$ man of height $170 \, cm$ wants to see his complete image in a plane mirror (while standing). His eyes are at a height of $160 \, cm$ from the ground. Which of the following statements are correct?
$(a)$ Minimum length of mirror is $80 \, cm$
$(b)$ Minimum length of mirror is $85 \, cm$
$(c)$ Bottom of the mirror should be at a height $80 \, cm$
$(d)$ Bottom of the mirror should be at a height $85 \, cm$

$A$ mirror is placed at a distance of $60 \ m$ from the base of a tower. The angle between the top of the tower and the top of its image is $90^o$. Find the height of the tower in $m$.

$A$ thick plane mirror shows a number of images of the filament of an electric bulb. Of these,the brightest image is the

$A$ plane mirror produces a magnification of