Chapter 24 & 25

Geometrical Optics &
Physical Optics

Sign Convention for Spherical Mirrors
	Sign
Quantity	+	–
	Left of V, real object	Right of V, virtual object
	Left of V, real image	Right of V, virtual image
f	Concave Mirror	Convex Mirror
R	C right of V, convex	C left of V, concave
	Erect object	Inverted object
	Erect image	Inverted image
	Erect image	Inverted image

Images of Real Objects Formed by Spherical Mirrors
		Concave
Object		Image
Location	Type	Location	Orientation	Relative Size
	Real		Inverted	Minified
	Real		Inverted	Same Size
	Real		Inverted	Magnified
	Virtual		Erect	Magnified
		Convex
Object		Image
Location	Type	Location	Orientation	Relative Size
Anywhere	Virtual		Erect	Minified

Images Formed by Concave Spherical Mirrors

Example 7

Use a ray diagram to find the location, size, and orientation of the image formed by a concave mirror when the object is between the mirror and the focal point.

Solution:

Example 8

The concave side of a spoon has a focal length of 5.00 cm. Find the image distance for this "mirror" when the object distance is (a) 25.0 cm, (b) 9.00 cm, and (c) 2.00 cm.

Solution:

Solving the Mirror Equation for the image distance:

Example 9

A convex mirror has a 20.0 cm radius of curvature. Find the image distance for this mirror when the object distance is 6.33 cm.

Solution:

Find the focal length first, f = -10.0 cm then find the image distance:

Example 10

After leaving some presents under the tree, Santa notices his image in a shiny, spherical Christmas ornament. The ornament is 8.50 cm in diameter and 1.10 m away from Santa. Curious to know the location and size of his image, Santa consults a book on physics. Knowing that Santa likes to "check it twice," what results should he obtain, assuming his height if 1.75 m?

Solution:

Find the focal length:

Find the image distance:

Find the magnification:

Find the image height:

Reflecting Telescopes

Telescopes 1

Telescopes 2

On to Polarization