RAY DIAGRAMS FOR CONCAVE MIRRORS

Grade 10 Science – Optics UnitCardinal Ambrozic C.S.S.

Curved Mirrors are everywhere

Cloud Gate (The Chicago Bean) • Made by an artist Anish

Kapoor•168 stainless steel sheets• appears seamless•Inspired by liquid Mercury

•Convex outer portion

•Concave inner portion

A concave mirror is a mirror in which the reflecting surface is caved in

Another name for the concave mirror is a CONVERGING MIRROR.

EXAMPLES: Inside of a spoon Used in headlights Makeup Mirror

Concave Mirrors

CENTRE OF CURVATURE (C) - The centre point of a sphere that forms the curved mirror

PRINCIPAL AXIS (PA) – A horizontal line (90⁰) from the centre of curvature to the centre of the mirror

VERTEX (V) - The point where the principal axis meets the curved mirror.

CURVED MIRROR TERMS

FOCAL POINT (F) - A point half-way between the centre of curvature and the vertex where all parallel light rays come together.

FOCAL LENGTH (f) - The distance or length between the focal point and the vertex.

If you make part of the inner surface of the circle reflective, you create a concave mirror

C F V

f

Principal Axis

1. Place the bottom of the object on the principal axis.

2. Draw three incident rays from the top of your object and their respective reflected rays

3. Draw the image so that the bottom is on the principal axis and the top is where the 3 rays meet.

4. Determine the SALT characteristics of the image

Drawing Ray Diagrams for Concave Mirrors:

Refer to SMARTNote: Reflection Rules for Concave Mirrors

Drawing Incident and Reflected Rays in Curved Mirrors

C F

VPA

Mirror

S LargerA InvertedL In front of mirrorT Real

RAY DIAGRAM #1: Object between F and C

C F

VPA

Mirror

S SmallerA InvertedL In front of mirrorT Real

RAY DIAGRAM #2: Object beyond C

C F

VPA

Mirror

S LargerA UprightL Behind mirrorT Virtual

RAY DIAGRAM #3: Object between concave mirror and F