Answer to Question #102722 in Optics for sridhar

Question

A girl of height 150cm with her eye level at 140cm stands in front of a plane mirror of height 75cm fixed to a wall.The lower edge of the mirror is at a height of 85cm above her feet level.The height of her image the girl can see in the mirror is

Answer 1

We need to find the pat of the mirror between

$$y_1=140(0.5)=70\ cm, y_2=140\ cm.$$

$$x=70-(85-70)=55\ cm$$

The height of image is

$$h=\frac{55}{70}150\approx 120\ cm$$