A boy with a mouth 5 cm wide stands 2 m away from a plane mirror. Where is his image and how wide is the image of his mouth ?
Height of mouth = 5cm
Mouth mirror distance = 2m
Second law of reflection says, angle of incidence is equal to the angle of reflection.
Thus, the image will form 2 m behind the mirror and the width of the image of boy's mouth will be 5 cm.