20.2. Concave and Convex Mirrors http://www.ck12.org
FIGURE 20.8
FIGURE 20.9
Reflection on a shiny curved spoon.Focal length(f): The distance from the center of the mirror to the focal point.
The principal axis(P): A straight line drawn perpendicularly to the plane of the mirror which passes through the
mirror’s center.
The radius of curvature(RC): The radius of the sphere (from pointcto the mirror) from which the mirror was made.
In order for the reflected rays to have a (nearly) common focus, the incidence angles must be small. This condition