chapter 18 reading quiz ray optics - home - physics...
TRANSCRIPT
• The ray model of light
• Reflection
• Refraction
• Dispersion
• Ray tracing for lenses
Chapter 18
Ray Optics
Topics:
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
• Ray tracing for lenses
• Ray tracing for mirrors
Sample question:
Why are there two images of this turtle in an aquarium, and why
does each image appear to be a different size?
Why are there two images of this turtle in an aquarium, and why
does each image appear to be a different size?
Slide 18-1
Reading Quiz
1. When an object like a tree is illuminated by the sun, and you are looking toward the tree, light rays leave the object
A. only from points at the top and base of the tree, but in
every direction.
B. from every point on the surface of the tree, but only toward
your eyes.
C. only from points at the top and base of the tree, but only
toward your eyes
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
toward your eyes
D. from every point on the surface of the tree and in every
direction.
When an object like a tree is illuminated by the sun, and you are looking toward the tree, light rays leave the object
only from points at the top and base of the tree, but in
from every point on the surface of the tree, but only toward
only from points at the top and base of the tree, but only
from every point on the surface of the tree and in every
Slide 18-2
1. When an object like a tree is illuminated by the sun, and you
are looking toward the tree, light rays leave the object
Answer
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
D. from every point on the surface of the tree and in every direction.
When an object like a tree is illuminated by the sun, and you
are looking toward the tree, light rays leave the object
from every point on the surface of the tree and in every
Slide 18-3
Reading Quiz
2. A light ray can change direction when going from one material
into another. This phenomenon is known as
A. reflection.
B. absorption.
C. refraction.
D. scattering.
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
2. A light ray can change direction when going from one material
into another. This phenomenon is known as
Slide 18-4
2. A light ray can change direction when going from one material into another. This phenomenon is known as
C. refraction.
Answer
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
2. A light ray can change direction when going from one material into another. This phenomenon is known as
Slide 18-5
The Ray Model of Light
Light rays travel in straight lines.
Light rays can cross.
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
An object is a source of light rays.
A light ray travels forever unless it A light ray travels forever unless it
interacts with matter.
The eye sees by focusing a bundle of rays.
Slide 18-6
Sources of Light Rays: Self
A ray source
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
An extended source
Sources of Light Rays: Self-Luminous Objects
A point source
A parallel-ray source
Slide 18-7
Seeing Objects
Seeing a point or extended source
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Seeing a ray source
Seeing an object by scattered light
Seeing a point or extended source
Slide 18-8
Shadows
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-9
If the aperture is very small, how far apart on the screen built into the left side of the box are the images of the pointgreen light sources?
Example
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
If the aperture is very small, how far apart on the screen built into the left side of the box are the images of the point-like red and
Slide 18-10
If the aperture is a circle 1 cm in diameter, what are the size and
shape of the image of the green pointneed to know how far below the center of the aperture that source is?
Example
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
If the aperture is a circle 1 cm in diameter, what are the size and
shape of the image of the green point-like light source? Do you need to know how far below the center of the aperture that source
Slide 18-11
The Law of Reflection
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
1.The incident ray and the
reflected ray are in the same
plane normal to the surface,
and
Slide 18-12
and
2.The angle of reflection
equals the angle of incidence:
θr = θi .
The Plane Mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-13
Refraction
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-14
Snell’s Law of Refraction
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
n1 sinθ1 = n2 sinθ2
Slide 18-15 Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-16
What is the index of refraction of tthe figure?
Example
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
f the plastic if a ray is refracted as in
Slide 18-17
Total Internal Reflection
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
1 2c
1
sinn
nθ
−
=
Slide 18-18
Color and Dispersion
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-19
Thin Lenses and Ray Tracing
The focal point of a converging lens
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
The focal point of a diverging lens
Thin Lenses and Ray Tracing
Slide 18-20
Three Important Sets of Rays: Converging Lenses
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Three Important Sets of Rays: Converging Lenses
Slide 18-21
Ray Tracing: Real Images
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-22
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-23
Which of these ray diagrams is possibly correct?
Checking Understanding
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Which of these ray diagrams is possibly correct?
Slide 18-24
Which of these ray diagrams is possibly correct?
Answer
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Which of these ray diagrams is possibly correct?
Slide 18-25
Magnification
m =′h
h=
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
=′s
s
Slide 18-26
Ray Tracing: Virtual Images
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Ray Tracing: Virtual Images
Slide 18-27
Three Important Sets of Rays: Converging Lenses
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Three Important Sets of Rays: Converging Lenses
Slide 18-28
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-29
Checking Understanding
In this figure the image is produced by a lens. At which position A–E is the lens?
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
In this figure the image is produced by a lens. At
Slide 18-30
In this figure the image is produced by a lens. At
which position A–E is the lens?
Answer
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
In this figure the image is produced by a lens. At
Slide 18-31
Spherical Mirrors and Ray Tracing
The focal point of a concave mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
The focal point of a convex mirror
Spherical Mirrors and Ray Tracing
Slide 18-32
Three Sets of Special Rays for a Concave Mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Three Sets of Special Rays for a Concave Mirror
Slide 18-33
A Real Image Formed by a Concave Mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
A Real Image Formed by a Concave Mirror
Slide 18-34
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-35
Three Sets of Special Rays for a Convex Mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Three Sets of Special Rays for a Convex Mirror
Slide 18-36
Ray Tracing for a Convex Mirror
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley.
Ray Tracing for a Convex Mirror
Slide 18-37 Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Slide 18-38