4 4 IMAGES IN CURVED MIRRORS Types of

Types of Curved Mirrors: � Concave: � Inner � surface of curved mirror is

Terminology � Centre of Curvature (C) � Centre of the sphere whose surface is

� Focus (F) � The point where parallel light rays come together on a

Real Image � � An image that can be seen on a screen as

Locating Images in Converging (Concave) Mirrors � Draw two incident light rays from the

Object beyond C S- smaller A- inverted L- b/t F and C T- real

Object at C S- same A- inverted L- at C T- real

Object between F and C S- larger A- inverted L- beyond C T- real

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

Object between V and F -extend reflected rays back behind mirror S- larger A-

Convex Mirror � � Light rays DIVERGE on the mirror and meet at a

Reflection of a Convex Mirror 1. A ray parallel to the PA is reflected

S - smaller A – upright L – behind mirror T- virtual Object will

Slides: 17

Download presentation

4. 4 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 principal axis intersects the mirror

� Focus (F) � The point where parallel light rays come together on a concave mirror. It is exactly halfway between C and V.

Real Image � � An image that can be seen on a screen as a result of light rays actually arriving at that particular 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 F 2. One through C, then reflects back upon itself � � 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

Object beyond C S- smaller A- inverted L- b/t F and C T- real

Object at C S- same A- inverted L- at C T- real

Object between F and C S- larger A- inverted L- beyond C T- real

Object at F -cannot run a ray through the focal point so run one through the centre of curvature - Reflected rays do not intersect as they are parallel. SA- *no clear L-image forms* T-

Object between V and F -extend reflected rays back behind mirror S- larger A- upright L- behind mirror T- virtual

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 - smaller A – upright L – behind mirror T- virtual Object will always be in front of mirror and therefore image will ALWAYS be smaller, upright, behind mirror and virtual

V F C