# PHYS 2212 Module 14.2

## Spherical Mirrors 14.2 Spherical Mirrors

### Learning Objectives

By the end of this section, you will be able to:

• Describe image formation by spherical mirrors.
• Use ray diagrams and the mirror equation to calculate the properties of an image in a spherical mirror.

### Images Formed by Spherical Mirrors

We already briefly discussed how you see an image formed by a flat mirror. Now we will look at images from curved mirrors. You actually see these all the time, but maybe never thought about how they work. In this picture on the left, a makeup mirror is a concave (converging) mirror. The picture on the right shows a convex (diverging) mirror.

A concave mirror is a curved mirror whose reflective side is on the inside of the curve, like here:

A convex mirror is a curved mirror whose reflective side is on the outside of the curve, like here: Practice!

### Mirror Equations

#### The Mirror Equation and Magnification

The mirror equation is:

and the magnification is:

The sign conventions are: Practice! Discuss!

An automobile rear-view mirror shows an image of a truck at a time when the truck is 3.0 m from the mirror. The focal length of the mirror is -0.58 m.

(a) Find the position of the image of the truck.

(b) Find the magnification of the image.