The image of an object approaching a convex mirror of radius of curvature $20 \ m$ along its optical axis is observed to move from $25/3 \ m$ to $50/7 \ m$ in $30 \ s$. The speed of the object in $km/hr$ is

There are two plane mirrors with reflecting surfaces facing each other. The mirrors are moving with speed $v$ away from each other. $A$ point object is placed between the mirrors. The velocity of the $n$-th image will be

If an observer is moving away from a stationary plane mirror at a speed of $6 \, m/s$,then the speed of the image with respect to the observer is ..... $m/s$.

The speed at which the image of a luminous point object is moving,if the luminous point object is moving at speed $v_0$ towards a spherical mirror along its axis,is (Given: $r =$ radius of curvature,$u =$ object distance):

An object is moving in front of a mirror as shown in the figure. Match the items in Column-$I$ with the values in Column-$II$.

$(i)$ Velocity of image	$(a) \; 2 \; m/s$
$(ii)$ Velocity of image with respect to mirror	$(b) \; 20 \; m/s$
$(iii)$ Velocity of image with respect to object	$(c) \; 11 \; m/s$
$(iv)$ Velocity of image if mirror is stopped	$(d) \; 22 \; m/s$

$A$ plane mirror is placed along the $x$-axis facing the negative $y$-axis. The mirror is fixed. $A$ point object is moving with a velocity of $3\hat{i} + 4\hat{j}$ in front of the plane mirror. Find the relative velocity of the image with respect to the object.