9.2 R EFLECTION AND M IRRORS Essential Questions: 1. What Are the Kinds of Reflections? 2. What Types of Images Do Mirrors Produce?

W HAT A RE THE K INDS OF R EFLECTION ? Light obeys the law of reflection. The angle of the reflection equals the angle of incidence. Snell’s Law

W HAT A RE THE K INDS OF R EFLECTION ? Regular reflection occurs when parallel rays of light hit a smooth surface. All of the light reflects at the same angle. This produces an image, which is a copy of an object formed by reflected or refracted rays of light.

W HAT A RE THE K INDS OF R EFLECTION ? Diffuse reflection occurs when parallel rays of light hit an uneven surface. Even the flat surface of a sheet of paper has enough bumps on a small scale to diffuse light.

W HAT T YPES OF I MAGES D O M IRRORS P RODUCE ? A plane mirror is usually a flat piece of glass with a silver colored coating on one side. This creates a virtual image, which is an image that does not exist, but forms where light seems to come from. A plane mirror produces a virtual image that is upright and the same size as the object.

W HAT T YPES OF I MAGES D O M IRRORS P RODUCE ? Concave mirrors have a reflective surface that curves inward that can produce a virtual or real image. A real image forms when light rays actually meet.

C ONCAVE M IRRORS Notice that the incoming light rays are parallel to the optical axis, an imaginary line that divided a mirror in half. The focal point is that point at which reflected parallel light rays meet.

C ONCAVE M IRRORS Real and Virtual Images The figures show how a concave mirror can produce both real and virtual images.

C ONVEX M IRRORS A convex mirror is a mirror with a surface that curves outward. This produces a virtual image that is always smaller than the object.