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Chapter 23

Mirrors and Lenses

1. Flat Mirrors

2. Spherical Mirrors

3. Thick lenses

4. Thin lenses

5. Aberrations

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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

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Concave Mirror: Notation and Image formed

� R

� p

� q

� f

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Convex Mirror: Notation and Image formed

� R

� p

� q

� f

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Sign Conventions for Mirrors

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Ray Diagrams

� How do I draw Ray diagrams?

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Ray Diagram for Concave Mirror, p > R

� Object � Image

� Type� Distance� Orientation� Size

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Ray Diagram for a Concave Mirror, p < f

� Object � Image

� Type� Distance� Orientation� Size

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Ray Diagram for a Convex Mirror

� Object � Image

� Type� Distance� Orientation� Size

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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.

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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?

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Images Formed by Refraction

� When n2 > n1,

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Sign Conventions for Refracting Surfaces

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Atmospheric Refraction: Sunset and Mirages

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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?

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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 > f

� Image

� Type

� Orientation

� Distance

� Size

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Ray Diagram for Converging Lens, p < f

� Image

� Type

� Orientation

� Distance

� Size

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Focal Length of a Diverging Lens

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Ray Diagram for Diverging Lens

� Image

� Type

� Orientation

� Distance

� Size

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Lens Equations

� What can it do?

� How do I calculate the magnification?

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Sign Conventions for Thin Lenses

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Lens Maker’s equation

� What can it do?

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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.

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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

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Combination of Thin Lenses

� Image by first lens

� Object for the second lens

� The final image

� What if?

� What is the Total magnification?

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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.