Plane Mirror a mirror with a flat surface

Plane Mirror: a mirror with a flat surface Plane mirrors create virtual images. A virtual image is a point at which light rays appear to diverge without doing so.

Image Point Source – point at which the object appears to be in the mirror from any vantage point in front of the mirror.

A similar cylinder can be placed behind a mirror to indicate the image point of the cylinder placed in front of the mirror

The image formed by a plane mirror appears to be at a distance behind the mirror that is equal to the distance of the object in front of the mirror.

Converging Mirrors – A mirror where parallel light rays will intersect at a common point (focal point) upon reflection. Such mirrors are also referred to as a Concave Mirrors Diverging Mirror – A mirror where parallel rays diverge upon reflection, as though the reflected rays come from a focal point behind the mirror. Such mirrors are also referred to as Convex Mirrors

Ray Diagrams Three types of rays used to find the location and magnitude of an image Parallel Ray is a ray that is incident along a path parallel to the optic axis and is reflected through the focal point Chief Ray or Radial Ray is a ray incident through the center of curvature (C). Since it is incident normal to the mirror’s surface, this ray is reflected back along its incident path, through C. C is the center of curvature Focal Ray is a ray that passes through point and is F isthe focal point reflected C =parallel 2 f to the optic axis f is the focal length

Focal Point A Focal Point is a point location where parallel rays that are reflected from a mirror meet.

Images Formed with Concave Mirrors Parallel Ray and Focal Ray are needed to determine the location and size of object.

Images Formed with Concave Mirrors When object Beyond C: Image is Real Inverted Smaller do > di ho > h i

Images Formed with Concave Mirrors When object is at C Image is Real Inverted Same Size do = di ho = h i

Images Formed with Concave Mirrors When object is between C and F Image is Real Inverted Larger do < di ho < h i

Images Formed with Concave Mirrors When object is at F No Image

Images Formed with Concave Mirrors When object is between F and Mirror Image is Virtual Erect Larger do < di ho < h i

Object Location

Overview Object Image

Convex Mirrors and Images All Images are Virtual Erect Smaller do > di ho > h i

r o f ns Sig Mirror Equations f = Focal Distance di = Image Distance o= Object Distance The focal length f is positive for concave mirrorsdand negative for convex mirrors A more useful Common to find image location Equation The object distance do is always positive The image distance di is always positive for a real image (same side of mirror as Mbehind = Magnification object) and negative for a virtual image (forms the mirror) h i = Height of Image The magnification M is positive for an upright image and negative for an inverted image ho = Height of Object