Mirrors

Spherical Mirrors

Mirrors formed with a smooth curved shape, a section of a sphere

Center of Curvature

The center of the circle, of which the mirror represents a small arc

Focus

The point where parallel light rays converge and are always found on the inner part of the “circle”, in which the mirror is a small arc, and the focus of a mirror is one-half of the radius

Vertex

Where the mirror crosses the principal axis

Principal Axis

A line drawn through the vertex, focus, and center of curvature of the mirror on which the object rests

Focal Length

The distance from the focus to the vertex of the mirror

Radius of Curvature

The distance from the curvature’s center to the mirror’s vertex. It corresponds to the radius of the circle

Plane Mirror

• A flat mirror that reflects light rays as they approach the mirror’s surface

• The measurement of the incident angle will always be equal to the measure of the reflected angle

• Images formed:

  • Same as the object

  • Same distance as the object is from the mirror

  • Always erect

  • Virtual (found behind the mirror)

  • Laterally reversed, left to right

Concave Mirror

• Light rays that strike the mirror surface are reflected to converge or come together at a point

• Uses:

  • Shaving mirrors

  • Make-up mirrors

  • Microscopes

  • Ophthalmoscope

  • Headlights

  • Solar furnaces

• Can form real and virtual images depending on the objects distance from the mirror:

  • Far: real, inverted, smaller than the object

  • Near: virtual, erect, larger than the object

Convex Mirror

• Cause light rays to diverge or spread out after reflection

• Uses:

  • Telescopes

  • Fisheye lenses

  • Hallway safety mirrors

  • Rearview side mirror

• Imagine formed is virtual, erect, and smaller than the object