11.9 IMAGES IN CURVED MIRRORS

Types of Curved Mirrors: Concave:

Inner surface of curved mirror is reflective Convex:

Outer surface of curved mirror is reflective

Terminology Centre of Curvature (C)

Centre of the sphere whose surface is used to make the mirror

Principal Axis (PA) Line going through the centre of curvature and the

centre of the mirror Vertex (V)

Point where the PAintersects the mirror

Focus (F) The point where parallel light rays come

together or converge on a concave mirror. It is exactly half way between C and V.

Real Image

An image that can be seen on a screen as a result of light rays actually arriving at the location

Video- Vital Science: Curved Mirrors

Locating Images in Converging (Concave) Mirrors

Draw two incident light rays from the top of the object 1. One parallel to the PA, then reflects through F2. One through F, then reflects parallel to the PA

The point where the two reflected rays intersect is where the image will form

NOTE: you could use all four types of incident rays but only two are needed for a point of intersection

S- smaller A- invertedL- b/t F and CT- real

Object beyond C

S- A- L-T-

S- sameA- invertedL- at CT- real

Object at C

S- A- L-T-

S- largerA- invertedL- beyond CT- real

Object between F and C

S-A-L-T-

*no clear image forms*

- Reflected rays do not intersect as they are parallel.

Object at F-cannot run a ray through the focal point so run one through the centre of curvature

S- largerA- uprightL- behind mirrorT- virtual

Object between V and F

-extend reflected rays back behind mirror

Convex Mirror Light rays DIVERGE on the mirror and

meet at a VIRTUAL FOCUS behind the mirror

Large viewing area but can cause some distortion

Used to view large areas like in a variety store

Produce smaller upright virtual images

Reflection of a Convex Mirror

1. A ray parallel to the PA is reflected as if it had come through the focus

2. A ray aimed at the focus will reflect back parallel to the PA

3. A ray aimed at the centre of curvature is reflected back upon itself

S - smallerA – uprightL – behind mirrorT- virtual

Object will always be in front of mirror and therefore image will ALWAYS be smaller, upright, behind mirror and virtual

F CV