A small convex security mirror is mounted in a store aisle. An object is located 25 cm in front of the mirror on its principal axis; the mirror’s focal length is 15 cm (measured as a positive quantity according to the standard sign convention).
Without performing any numerical calculations, analyse how a complete ray diagram would represent the formation of the image.
(a) Describe, in words, the paths of the three principal rays that would be drawn from the tip of the object to locate the image.
(b) Using only geometrical reasoning based on the rays identified in part (a), determine whether the image is real or virtual, upright or inverted, and enlarged or reduced. Justify each of your conclusions.
(c) Explain why the image appears to form behind the reflective surface even though no light actually converges there.