A small luminous point O is placed in front of a vertical plane mirror.
(i) Draw a neat labelled ray diagram to show the formation of the image of point O in the plane mirror.
(ii) Prove that the perpendicular distance of the image from the mirror is equal to the perpendicular distance of the object from the mirror.
(iii) If O is kept 50cm in front of the mirror, calculate the distance between the object and its image.