Topic 1 Reflection

(a) State the law of reflection.

(b) Show that the focal length of a concave mirror is half the radius of curvature for small angles of incidence.

Topic 2 Refraction

(a) State Snell's law.

(b) Express the index of refraction in terms of the speed of light.

Topic 3 Lenses

(a) Derive the lens equation.

(b) Show that magnification equals the ratio of image to object distances.

(c) What's a diopter?

Examples

A makeup mirror provides a magnification of 2 when held at 50 cm from your face. What is the image position and focal length of the mirro?

What is the speed of light in diamond, index of refraction of 2.4?

My eyeglasses have a -6 diopter correction. What is the focal length? What is the image position for an exam paper held at 20 cm from my nose?

Textbook Problems