What are the types of mirrors?

$A$ point source of light $S$ at a distance $d$ from the screen $A$ produces light intensity $I_0$ at the centre of the screen. If a completely reflecting mirror $M$ is placed at a distance $d$ behind the source as shown in the figure,treating the object and its image as incoherent with each other,find the intensity at the centre of the screen.

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 object is placed mid-way between two plane mirrors at a distance $a$ apart. The plane mirrors form an infinite number of images due to multiple reflections. The distance between the $n^{th}$ order images formed in the two mirrors is

$A$ 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.

$A$ light ray makes an angle of $10^{\circ}$ with the horizontal. It is incident on a plane mirror which makes an angle $\theta$ with the horizontal. If the reflected ray travels in the vertically upward direction,then $\theta = .....^{\circ}$