Question

Figure shows the plane (top view) of a cubical room, with wall $CD$ as a plane mirror; each side of the room is $3metres$ in length. A camera $P$ is placed at the mid point of the wall $AB$. At what distance should the camera be focused to photograph the image of an object placed at $A$?

Answer 1

To find

$4F$ What location camera should be focused ?

Location of Image of object kept at point $A$ will be $3m$ below the plane mirror.

So camera will be focused at distance $=PA$

$PA=\sqrt{(6{)}^2+{\left(\frac{3}{2}\right)}^2}$

$=\sqrt{36+\frac{9}{4}}$

$=6.18m>6m$