Physics Chapter 17:Reflection and Mirrors A smooth surface reflects rays in straight lines and forms a clear image…this is called a specular reflection. Rough surfaces do not reflect rays in straight, parallel lines and does not form a clear image… this is called a diffuse reflection. Image orientation, on a plane mirror, is left-right reversed. Look at a letter e in a mirror to see this orientation.

Curved Mirrors A concave mirror is one that has the shiny side on the inside of the bowl shape. To show how reflections and images occur on mirrors, we show a ray diagram…

Notice the key points of the ray diagram… Notice the key points of the ray diagram…. Principal axis, focal point(C/2), center of curvature(C) , radius of curvature (r), object, image,ray 1 (purple), and ray 2 (green). See the ray-diagram rules on page 473!

Ray Diagram Rules for Real Images https://www.youtube.com/watch?v=tcgT4PcVXNo Link for 3 minute YouTube video on Ray Diagrams. 1 Draw ray 1 parallel to the principal axis, bounce off of the mirror and through the focal point. 2. Draw ray 2 through the focal point, bounce off of the mirror and then parallel to the principal axis. 3. Ray 3 is the principal axis. Your image is between the point where rays 1 and 2 intersect, and the principal ray, for a real image.

Real Image vs Virtual Image A real image, for mirrors, is in front of the mirror, and a virtual image is behind the mirror. Virtual images are upright and usually larger than the object, on curved mirrors. Real images are usually inverted and smaller than the object on curved mirrors. On a flat mirror, the image is virtual and is the same size as the object.

Ray Diagrams with Virtual Images 1. Ray 1 is parallel and through the focal point, but the focal point ray must be extended behind the mirror to meet ray 2. 2. Ray2 is through the focal point and then parallel, but the parallel line must be extended behind the mirror to meet ray 1. 3. The image will be behind the mirror, upright, between the principal ray and the intersection or rays 1&2.

Convex Mirrors A convex mirror is one that has the bottom, or back-side of the bowl mirrored. Convex mirrors ray diagrams….

Ray Diagram for a Convex Mirror