Question

A convex mirror has a focal length of 18 cm . The image of an object kept in front of the mirror is half the height of the object. find the image and object distance.

Answer 1

$f=18cm$

Magnification$=m=\frac{1}{2}=\frac{-v}{u}$

$⟹v=\frac{-u}{2}$

$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

$\frac{-2}{u}+\frac{1}{u}=\frac{1}{f}$

$⟹u=-f=-18cm$

And, $v=9cm$