14.3: Images formed by Mirrors

Describe the image formed by a mirror.

14.3.A.1 Incident light rays parallel to the principal axis of a concave mirror will be reflected toward a common location, called the focal point.

14.3.A.2 Incident light rays parallel to the principal axis of a convex mirror will be reflected such that they appear to have originated from a common location behind the mirror, called the focal point.

14.3.A.3 The focal point of a plane mirror is an infinite distance from the mirror.

14.3.A.4 The focal point of a spherical mirror may be approximated as a point located on the principal axis of the mirror at a location halfway between the surface of the mirror and the center of the mirror’s radius of curvature.

14.3.A.5 A real image is formed by a mirror when light rays emanating from a common point are reflected and then intersect after reflection at a common point.

14.3.A.6 A virtual image is formed by a mirror when reflected light rays diverge such that they appear to have originated from a common point.

14.3.A.7 The location of an image depends on the focal length of the mirror and the distance between the object and the surface of the mirror.

• 14.3.A.7.i The location of a mirror’s focal point, an object near the mirror, and the image of the object formed by the mirror follow sign conventions that are used to determine those locations relative to the mirror itself.

• 14.3.A.7.ii The distance between the image formed and the plane mirror is equal to the distance between the object and the plane mirror.

14.3.8 The magnification of an image formed by a mirror is the ratio of the size of the image produced to the size of the object itself and depends on the locations of the object and image relative to the mirror.

14.3.8.9 Ray diagrams can be used to determine the location, type, size, and orientation of images formed by mirrors.