Review from last class

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Review from last class Complete in your notes.

1. A pinhole camera creates an image of a
   37-meter-tall tree. If the image is 2.4 cm tall
   and inverted, what is the magnification of the
   camera?
2. Mirrors divert light using ______________, lenses
   divert light using ______________.
3. Describe the difference between specular and
   diffuse reflection.

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Assignment 3/23 and3/24

• Turn in optical devices worksheet

Homework Read 20.3 and 20.4 Page 596, 1-13, 29,
30, 31, 52, 55,
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Ray Diagrams (3/25 and 3/26)

• Mirrors

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Reflection

• Reflection from a mirror

Normal
Reflected ray
Incident ray
Angle of reflection
Angle of incidence
Mirror
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• The Law of Reflection

Angle of incidence Angle of reflection
In other words, light gets reflected from a
surface at THE SAME ANGLE it hits it.
The same !!!
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Flat Mirrors
Angle of reflection
Angle of incidence

Normal
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Flat Mirrors
The converging reflected rays indicate the
location of the image

• If the rays leave the optical system
  and appear to come from some point in space, the
  point they appear to come from is a virtual image.

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Image Descriptions

• How can we describe this image?
• Is it upright or inverted?
• Is it magnified or unmagnified?
• Is it virtual or real?

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Image Description

• This is an UPRIGHT, UNMAGNIFIED AND VIRTUAL image

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Ray Diagramsfor spherical mirrors

• Rules for drawing a ray diagram
• Draw an incident ray parallel to the principal
  axis, then a reflected ray through the focal
  point
• Draw an incident ray through the focal point,
  then parallel to the principal axis
• Draw a final line through the center point and
  back along itself

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Spherical Mirrors - Concave
C
F

• Image is REAL, INVERTED, and DEMAGNIFIED !!!

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Spherical Mirrors ConcaveObject Inside the
Focal Point
F
C

• Image is VIRTUAL, UPRIGHT, and MAGNIFIED

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Spherical Mirrors - Convex
C
F

• Image is VIRTUAL, UPRIGHT, and DEMAGNIFIED

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Equations

• 1/f 1/do 1/di
• 1/ focal length 1/object distance 1/image
  distance
• m - di/do
• Magnification - image distance / object
  distance

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Homework