Concave Mirrors

Objectives Know the three principal rays for a concave mirror. Use the principal rays to locate the image of an object in front of a concave mirror. Correctly classify images formed by concave mirrors. Understand why different types of images can be formed with a concave mirror.

Do You Know? Can a concave mirror form an image that is not behind the mirror? What might this image’s characteristics be? You will know the answer to this question at the end of this lesson.

Vocabulary Concave Mirror – a mirror that is a spherical surface, silvered on the outside of the sphere. Principal Axis – a horizontal line that passes through the center of the mirror. Focal Point – the point at which incident parallel light rays cross the principal axis. The distance from this point to the center of the mirror is called the focal length.

Vocabulary Center of Curvature – the center of the sphere formed by the mirror. ◦ The center of curvature is double the focal length. Real image – an image formed by light rays that intersect. This type of image can be viewed on a screen.

Mirror Lab Safety Considerations – Keep the laser parallel to the tabletop at all times. Do not point the laser at anyone.

Mirror Physlet Link to virtual optical bench Link to concave mirror simulation