Concave and Convex Mirrors

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Concave and Convex Mirrors
Grade 9 and 10 Science Mr. MacMillan
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Properties of Concave Mirrors

• A mirror whose reflecting surface curves inward
• When you look at objects in a concave mirror such
  as people, buildings or cars the images are
  distorted

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Images in Concave Mirrors
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Ray Diagrams

• Principal axis
• A line that passes through the centre of
  curvature, C, of the mirror and is normal to the
  centre of the mirror
• Focal point
• The point on the principal axis through which
  reflected rays pass when the incident rays are
  parallel to and near the principal axis
• Focal length
• The distance between the vertex of a mirror and
  the focal point half the distance from the
  vertex to the centre of curvature

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Principal Axis
Focal Length
Focal Point
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Mirror and Magnification

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Example

• A convex surveillance mirror in a convenience
  store has a focal length of -0.40m. A customer,
  who is 1.7m tall, is standing 4.5 m in front of
  the mirror.
• Calculate the image distance
• Calculate the image height.

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Properties of Convex Mirrors

• A mirror whose reflecting surface curves outward
• A convex mirror is a spherical mirror that has
  only a small centre region that gives images that
  are not distorted

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Images of Convex Mirrors
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Ray Diagrams