Transcript PHY2054-PPT24

Chapter 24
Geometric Optics
PowerPoint Lectures for
College Physics, Eighth Edition
Hugh D. Young and Robert M. Geller
Lectures by James L. Pazun
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Goals for Chapter 24
• To study reflections from a plane surface.
• To see how reflections from a spherical
surface add new features.
• To understand ray tracing and graphical
methods for all mirrors.
• To study refractions at spherical surfaces
and thin lenses.
• To adapt what we learned about ray tracing
to graphical methods for lenses.
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Reflections at a plane surface – Figure 24.1
Review key terms.
• object
• image
• real
• virtual
• distance to image
• distance to object
• magnification
• upright
• inverted
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Refractions deceive your eyes – Figures 24.2,3
As the eye follows rays back to the mirror surface, the brain
completes the path forming a virtual focus behind the mirror.
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Sign rules for images and objects – Figure 24.4
• The position of the
object and the
image determine
sign convention.
• See the yellow
box on the top of
page 805.
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Magnification – Figure 24.5
Height of image and object will determine the magnification.
See the yellow box on page 805.
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“Inverted” or “erect” defining terms – Figure 24.6
• The appearance of the image with respect to it’s object
reveals our description.
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Plane mirrors exhibit left-right reversal – Figure 24.7
Have you ever looked at some emergency service vehicles and
wondered what ECILOP or ECNALUBMA means? (Actually it’s
even harder, the letters are reversed in their presentation).
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Spherical mirrors – Figure 24.9
• Reflections from a spherical mirror depend on the
radius of curvature.
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Concave spherical mirrors – Figure 24.11
• Refer to the information in
the yellow box at the bottom of
page 808.
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The principal rays for mirror imaging – Figure 24.12
• Refer to the Conceptual Analysis 24.2 and Example 24.1 on page
810 of your text.
• These results are also obtained numerically with the mirror
equations of section 24.2.
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The convex spherical mirror – Figure 24.15
Tracing the principal rays to find the virtual image for a convex
spherical mirror.
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Reflection and production of paraxial rays – Figure 24.16
•This type of mirror is an excellent choice for clandestine
observation or automotive applications.
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The image formed by a convex mirror –Example 24.2
Refer to the worked example on page 812 of your text and help
Santa feel better about his image.
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Specific ray tracing for mirror analysis – Figure 24.19
• Refer to the yellow box on page 813 for a complete description.
• Refer also to the Problem-Solving Strategy 24.1
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A complete image construction - Example 24.3
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Refraction at spherical surfaces – Figure 24.21
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Glass rods in air or water – Examples 24.4, 24.5
The figure below refers to Example 24.4
The figure below refers to example 24.5
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Optical illusions from refraction – Figures 24.25, 26
The image at right refers
to worked Example 24.6
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The converging lens – Figure 24.27
The biconvex
lens shown is
but one in a
series of thin
lenses that
we will
examine by
shape and
ray tracing.
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Object and image for a converging lens – Figure 24.28
We will next find ourselves in a position to relate object and
image by tracing the principal rays as we did with mirrors.
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Lenses and left-right reversal – Figure 24.29
It can be shown that lenses do not produces the left-right reversal
that we observed with mirrors.
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Diverging lenses and foci – Figure 24.30
• The focal point is imaginary.
• Refer to Conceptual Analysis 24.3.
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Diverse shapes accommodate many uses – Figure 24.31
• Many different
arrangements may be
constructed depending
on the lens shape.
• Refer to Figures
24.32, 24.33, and
Quantitative Analysis
24.4.
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Examples with a plano-concave lens – Figure 24.34
• Follow the worked examples 24.7 and 24.8 on pages 824-825 of
your text.
This figure refers to example 24.7.
This figure
refers to
example
24.8.
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The principal rays for thin lenses – Figure 24.36
• The results shown here graphically may also be obtained with
the thin lens equations. Refer to pages 823-824.
• Refer to the yellow text box on page 826 for a description of the
principal rays.
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Examples of thin lens analysis – Figure 24.37
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Examples of thins lens imaging – Figure 24.38, 39
• Refer to Conceptual Analysis 24.5, the Problem Solving Strategy
24.2, Example 24.9 and Example 24.10.
This figure refers to
Conceptual Analysis 24.5.
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This figure refers to Example
24.10.