24 Geometric Optics

Water drop as a converging lens

Reflection at a Plane Surface

Image and ObjectRays diverging from one point P (object) recombine at point P’ by mirror or lens— an image formed.

Object & Image Distances 1. Object distance2. Image distance3. Real image4. Virtual image5. Magnification

Sign Ruless: The (real) object distance is positive. (The distance is negative for a virtual object.) s’: The image distance (s’) is positive for all real images and negative for virtual images. y and y’: Heights are positive if measured upward from the principal axis and negative if measured downward. m: Magnification is positive if the image is erect and negative when inverted. f: The focal length is positive for converging mirrors and lenses, and negative for diverging ones.

Reflection at a Spherical Surface

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11Mirror Equation

Focal Point & Focal Length-Concave

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Image Construction—Concave

Focal Point & Focal Length-Convex

Image Construction—Convex

Image Construction—Principal Rays

Image Construction—Practice

Refraction at a Spherical Surface

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How Deep is the Pool?

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Thin Lenses—Converging

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Thin Lenses—Diverging

Thin-Lens Equations

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Imaging thru Thin –Lens: Principal Rays

http://www.mtholyoke.edu/~mpeterso/classes/phys301/geomopti/lenses.html

Principal Rays: Practice

Summary: Reflection at a Plane Surface

Summary: Reflection at a Spherical

Surface

Summary: Graphical Methods for Mirrors

Summary: Refraction at a Spherical Surface & Thin

Lenses

Summary: Graphical Methods for Lenses

Example: The Eye’s Lens

The least distance of distinct vision (LDDV): 25 cm ~ 10 in

Mirror/Lens Equation

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LensThin

(-)convex or )( concave

mirror plane

Homework Ch24Problems:: 1, 4, 5, 6, 13, 20, 29, and 32

Answers to multiple choice problems

quiz(1) Construct the images using principal rays for a converging lens and a convex mirror, respectively. (2) Find the locations of images using lens/mirror equation (f = +5 or -5 cm, s = 8 cm).

Test 3 Grade Distribution

# of Students: 30Average: 12.8=64%

Test 3 Grade Distribution# of Students: 21Average: 11.7=59%