Mirrors and Lenses

1
Chapter 23

• Mirrors and Lenses
• Flat Mirrors
• Spherical Mirrors
• Thick lenses
• Thin lenses
• Aberrations

2
Mirrors and Lenses Notation and Image Types

• The object distance (p)
• The image distance (q)
• The lateral magnification (M)
• How do I calculate M
• What is a Real Image?
• What is a virtual Image?
• How do I find where the image is?
• The mirror equation

3
Concave Mirror Notation and Image formed

• R
• p
• q
• f

4
Convex Mirror Notation and Image formed

• R
• p
• q
• f

5
Sign Conventions for Mirrors
6
Ray Diagrams

• How do I draw Ray diagrams?

7
Ray Diagram for Concave Mirror, p gt R

• Object
• Image
• Type
• Distance
• Orientation
• Size

8
Ray Diagram for a Concave Mirror, p lt f

• Object
• Image
• Type
• Distance
• Orientation
• Size

9
Ray Diagram for a Convex Mirror

• Object
• Image
• Type
• Distance
• Orientation
• Size

10
Example

1. A concave shaving mirror is designed to get a
   virtual image which is twice the size of the
   object, when the distance between the object and
   the mirror is 15 cm. Determine the radius of
   curvature of the mirror.

11
Example

1. A convex spherical mirror with a radius of
   curvature of 10.0 cm produces a virtual image
   one-third the size of the real object. Where is
   the object?

12
Images Formed by Refraction

• When n2 gt n1,

13
Sign Conventions for Refracting Surfaces
14
Atmospheric Refraction Sunset and Mirages
15
Example

1. A small fish is swimming at a depth d below the
   surface of a pond. What is the aparaent depth of
   the fish as viewed from directly overhead?

16
Thin Lens Shapes

• Light
• Focal length
• Thickness

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More Thin Lens Shapes

• Light
• Focal length
• Thickness

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Focal Length of a Converging Lens
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Ray Diagram for Converging Lens, p gt f

• Image
• Type
• Orientation
• Distance
• Size

20
Ray Diagram for Converging Lens, p lt f

• Image
• Type
• Orientation
• Distance
• Size

21
Focal Length of a Diverging Lens
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Ray Diagram for Diverging Lens

• Image
• Type
• Orientation
• Distance
• Size

23
Lens Equations

• What can it do?
• How do I calculate the magnification?

24
Sign Conventions for Thin Lenses
25
Lens Makers equation

• What can it do?

26
Examples

1. A converging lens of a focal length 10.0 cm forms
   images of objects placed a) 30.0cm b)10.0cm and
   c)5.0cm from the lens. Find the image distance
   and describe the image in each case.

27
Examples

1. A diverging lens of a focal length 10.0 cm forms
   images of objects placed a) 30.0cm b)10.0cm and
   c)5.0cm from the lens. Find the image distance
   and describe the image in each case.

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Aberrations
29
Combination of Thin Lenses

• Image by first lens
• Object for the second lens
• The final image
• What if?
• What is the Total magnification?

30
Example

• Two converging lenses are placed 20 cm apart. If
  the first lens has a focal length of 10 cm and
  the second has a focal length of 20 cm, locate
  the final image formed of an object 30 cm in
  front of the first lens. Find the magnification
  of the system.