#### 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
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.
Reflections at a plane surface – Figure 24.1
Review key terms.
• object
• image
• real
• virtual
• distance to image
• distance to object
• magnification
• upright
• inverted
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.
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.
Magnification – Figure 24.5
Height of image and object will determine the magnification.
See the yellow box on page 805.
“Inverted” or “erect” defining terms – Figure 24.6
• The appearance of the image with respect to it’s object
reveals our description.
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).
Spherical mirrors – Figure 24.9
• Reflections from a spherical mirror depend on the
Concave spherical mirrors – Figure 24.11
• Refer to the information in
the yellow box at the bottom of
page 808.
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.
The convex spherical mirror – Figure 24.15
Tracing the principal rays to find the virtual image for a convex
spherical mirror.
Reflection and production of paraxial rays – Figure 24.16
•This type of mirror is an excellent choice for clandestine
observation or automotive applications.
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.
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
A complete image construction - Example 24.3
Refraction at spherical surfaces – Figure 24.21
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
Optical illusions from refraction – Figures 24.25, 26
The image at right refers
to worked Example 24.6
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.
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.
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.
Diverging lenses and foci – Figure 24.30
• The focal point is imaginary.
• Refer to Conceptual Analysis 24.3.
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.
Examples with a plano-concave lens – Figure 24.34
• Follow the worked examples 24.7 and 24.8 on pages 824-825 of
This figure refers to example 24.7.
This figure
refers to
example
24.8.
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.