Flat Mirrors

Reflection Diffuse reflection is reflection from a rough surface, such as notebook paper or the wall. Specular reflection is reflection from a smooth surface, such as a mirror or shiny metal. We will study specular reflection.

Angle of Reflection At what angle will the incoming ray reflect from the mirror? Angle of incidence () = Angle of reflection (’) By convention, angles are measured with a normal line. Angles with the surface are also equal.

Ray Diagram Ray 1 strikes the mirror and reflects at the same angle (90°). Ray 2 reflects at the same angle it strikes. Our eyes see the two reflected rays and many others. The brain assumes that they came from a common point, and the image is seen at that point.

Ray Diagram The image is behind the mirror. The image distance (q) equals the object distance (p). The image size (h’) equals the object size (h). The image is virtual, not real. Reflected rays do not actually meet, they only appear to come from a common point.

Flat Mirror Imagine a small mirror as shown. The man will only see the portion of his body shown. How would that change if he were closer to the mirror? Farther away? Try drawing a diagram similar to that shown.