Lesson Plan

State the law of reflection and apply it, measuring all angles from the normal

Distinguish specular reflection from diffuse reflection and explain why rough surfaces are visible from many angles

Explain how a plane mirror forms a virtual image and show that the image distance equals the object distance

Classify mirrors as concave or convex and predict the type and orientation of the image from the object's position relative to the focal point

Apply the lens/mirror equation, the magnification equation, and R = 2f to solve curved-mirror problems, using correct sign conventions

16.1

"The law of reflection states: The angle of reflection, $\theta_r$, equals the angle of incidence, $\theta_i$. ... The angles are measured relative to the line perpendicular to the surface at the point where the light ray strikes it. This perpendicular line is also called the normal line, or just the normal." "An image in a mirror is said to be a virtual image, as opposed to a real image. A virtual image is formed when light rays appear to diverge from a point without actually doing so." "A mirror that curves inward is called a concave mirror, whereas one that curves outward is called a convex mirror." "The basic equation that describes both lenses and mirrors is the lens/mirror equation $\frac{1}{f} = \frac{1}{d_i} + \frac{1}{d_o}$." "Magnification, m, is the ratio of the size of the image, h_i, to the size of the object, h_o. ... $m = \frac{h_i}{h_o} = \frac{-d_i}{d_o}$" "A negative d_i indicates a virtual image; a positive value indicates a real image. A negative h_i indicates an inverted image; a positive value indicates an erect image. For concave mirrors, f is positive; for convex mirrors, f is negative."