G t i O ti Geometric Optics
-
Upload
hoangkhuong -
Category
Documents
-
view
229 -
download
1
Transcript of G t i O ti Geometric Optics
G t i O tiGeometric Optics
Chapter 34January 26, 2012January 26, 2012
January 26, 2012 Physics 221 1
To access the applets shown in classppGo to the Study Area on the MasteringPhysics web site.
Chapter 34January 26, 2012January 26, 2012
January 26, 2012 Physics 221 2
Sign rules for greflection and refraction..
The object distance is positive if it is on the same side of the lens/mirror as the “incoming rays” (s is positive).
The image distance is positive if it is on the same side of the lens/mirror as the “outgoing rays” (s’ is positive).
The radius of curvature of a spherical surface is positive when the Center of Curvature is on the same side as the outgoing light (R is positive).
The “lateral” magnification of a system is defined as M = image height/object height = y(image)/y(object)
January 26, 2012 Physics 221 3
Summary of Mirror Equations
January 26, 2012 Physics 221 4
January 26, 2012 Physics 221 5
January 26, 2012 Physics 221 6
January 26, 2012 Physics 221 7
Thin Lenses….converging
Thin lenses are formed byth i t ti f tthe intersection of two surfaces.
Two Spherical Surfaces
A Sphere and a plane
January 26, 2012 Physics 221 8
and diverging lenses…
January 26, 2012 Physics 221 9
Focusing properties of a thin lens
S ll’ L i b d t h i t f f th l
Parallel light enters the lens.
Snell’s Law is obeyed at each interface of the lens.
g
Light is focused to a point after the lens
January 26, 2012 Physics 221 10
Lens Conventions..The focal length is positive for a converging lens and negativefor a diverging lens.
Th bj t di t i iti if it i th id f thThe object distance is positive if it is on the same side of the lens as the “incoming rays”.
The image distance is positive if it is on the opposite side of theThe image distance is positive if it is on the opposite side of the lens from where the “incoming rays” originate.
Image distances are positive for REAL images and negative for VIRTUAL iVIRTUAL images.
The height of the image is positive if it is “upright”.
January 26, 2012 Physics 221 11
The Lens Formula…
sy
sy
fsy
fy and '
'
'
'
=−
=
yy111
solving and and for ngsubstituti '
January 26, 2012 Physics 221 12fss111get we ' =+
For thin lenses…..
111fss111 ' =+fss
Image distanceObject distance Focal distance
January 24, 2012 Physics 221 13
Image distancej
For thin lenses…..
Lateral Magnification
s 'g
ss-m =s
January 24, 2012 Physics 221 14
Lensmaker’s equation…..
( ) ⎟⎟⎞
⎜⎜⎛
=+11111 n( ) ⎟⎟
⎠⎜⎜⎝
−−=+21
' 1s
s RR
n
⎞⎛
and
( ) ⎟⎟⎠
⎞⎜⎜⎝
⎛−−=
111f1
RRn
January 24, 2012 Physics 221 15
( ) ⎟⎠
⎜⎝ 21f RR
Examples
November 22, 2011January 24, 2012 Physics 221 16
Camera
January 24, 2012 Physics 221 17
The eye
January 26, 2012 Physics 221 18
The magnifier
January 26, 2012 Physics 221 19
Microscope
January 26, 2012 Physics 221 20
Telescope
January 26, 2012 Physics 221 21