18 1 Mirrors Katie Hanna Mirrors Mirrors are

18. 1 Mirrors Katie Hanna

Mirrors § Mirrors are the oldest optical instruments. § Prehistoric humans saw their faces reflected in the quiet water of lakes or ponds. § Almost 4, 000 years ago, Egyptians used polished metal mirrors to view their images. Hall of Mirrors Versailles. N. d. Visiting DC. Web. 1 Mar. 2011. <http: //www. visitingdc. com/paris/hall-of-mirrorsversailles. asp>.

Jean Foucault § Sharp, well-defined reflected images were not possible until 1857, when Jean Foucault, a French scientist, developed a method of coating glass with silver. Jean Foucault. N. d. Knowledge Rush. Web. 1 Mar. 2011. <http: //www. knowledgerush. com/kr/encyclo pedia/Leon_Foucault/>.

Objects and Images in Plane Mirrors

Plane Mirrors § A flat, smooth surface from which light is reflected by regular reflection rather than by diffuse reflection. § Bathroom Mirrors. § Regular Reflection. Plane Mirror. N. d. Ed. Informatics Org. , n. d. Web. 1 Mar. 2011. <http: //www. edinformatics. com/in ventions_inventors/mirror. htm>.

Objects § A source of spreading, or diverging light rays. § Every point on an object is a source of diverging light rays. § Anything reflected in a mirror. Object in a Mirror. N. d. Physics Problems to Challenge Understanding. Donald Simanek, n. d. Web. 1 Mar. 2011. <http: //www. lhup. edu/~dsimanek/scenario/ insight. htm>.

Images § An image is a reproduction of an image formed with mirrors or lenses. § The reflected image of an object. Image in a Mirror. N. d. Physics 20. Physics, n. d. Web. 2 Mar. 2011. <http: //www. sasked. gov. sk. ca/docs/ physics/u 3 b 22 phy. html>.

Virtual Images § A reflection in a normal mirror is actually a virtual image because the light rays do not actually converge on that point. Virtual Image. N. d. SMU Physics and Astronomy Demonstrations. SMU, n. d. Web. 2 Mar. 2011. <http: //www. ap. smu. ca/demos/ index. php? option=com_content view=article&id=122&Itemid=85

Erect Image § If the image and object are pointing in the same direction as each other, it is an erect image.

More Help § Mirrors Explained § http: //library. thinkquest. org/27356/p_mirror s. htm § http: //www. pa. msu. edu/courses/2000 fall/P HY 232/lectures/lenses/images. html § http: //www. physicsclassroom. com/class/re fln/u 13 l 4 a. cfm

Concave Mirrors

Concave Mirror § A concave mirror reflects light from its inner (“caved in”) surface. § Makeup mirror, Inside of a spoon Spoon. N. d. Smooth Harold. Blake Snow, n. d. Web. 2 Mar. 2011. <http: //www. smoothharold. co m/smoothharolds-top-10 spoon-songs/>.

Concave Mirror Image formation by a concave mirror. N. d. Spherical Mirrors. Richard Fitzpatrick, n. d. Web. 2 Mar. 2011. <http: //farside. ph. utexas. edu/ teaching/302 l/lectures/node 136. html>.

Spherical Concave Mirror § In a spherical concave mirror, the mirror is part of the inner surface of a hollow sphere. Spherical aberration in a concave mirror. N. d. Spherical Mirrors. Richard Fitzpatrick, n. d. Web. 2 Mar. 2011. <http: //farside. ph. utexas. edu/ teaching/302 l/lectures/node 136. html>.

Principal Axis § The principal axis is the straight line perpendicular to the surface of a mirror at its center.

Focal Point § The focal point is the point on a mirror where parallel rays meet. Focal point. N. d. Pirates and Revolutionaries. N. p. , n. d. Web. 2 Mar. 2011. <http: //piratesandrevolutionaries. blogspot. com/2009/07/ deleuzes-dance-iii-wonders-of-phenomena. html>.

Focal Length § The focal length is the distance from the focal point to the mirror along the principal axis.

Real Image § A real image is an image that rays actually converge and pass through. § Can be seen on a piece of paper or projected onto a screen.

Lens/Mirror Equation § You can use geometry to relate the focal length of the mirror, f, to the distance from the object to the mirror, do, and to the distance from the image to the mirror, di. Lens/Mirror Equation. N. d. Online Physics Lab. Physics. LAB, n. d. Web. 3 Mar. 2011. <http: //dev. physicslab. org/ Document. aspx? doctype=3&filename=Geometric. Optics_Mirror. Equation. xml>.

How to Solve the Equation § To solve the equation: § Use the least common denominator, dido. § Take the reciprocal of both sides. Lens/Mirror Equation 2. N. d. Online Physics Lab. Physics. LAB, n. d. Web. 3 Mar. 2011. <http: //dev. physicslab. org/ Document. aspx? doctype=3&filename=Geometric. Optics_Mirror. Equation. xml>.

Magnification § Magnification, m, is the ratio of the size of the image, hi, to the size of the object, ho. m = Magnification Equation. N. d. Physics Study Guide. N. p. , n. d. Web. 3 Mar. 2011. <http: //whs. wsd. wednet. edu/Faculty/Busse/Math. Home. Page/busseclasses/physics/ studyguides/chapter 14/Chapter 14 Study. Guide 2010. html>.

Spherical Aberration § The image formed by parallel rays in a large spherical mirror is a disk, not a point. This effect is called spherical aberration. § A parabolic mirror has no spherical aberration because all parallel rays are reflected to a single spot. Spherical Aberration. N. d. Refracting vs Reflecting. N. p. , n. d. Web. 3 Mar. 2011. <http: //wisp. physics. wisc. edu/astro 104/lecture 7/lec 7 h. html>.

Convex Mirrors

Convex Mirrors § A convex mirror is a spherical mirror that reflects light from its outer surface. § Wide-angle mirrors for safety and security. A Wide Angle Photo Of A Wide Angle Mirror Through A Wide Angle Mirror. N. d. Flickr. Yahoo! Inc. , n. d. Web. 2 Mar. 2011. <http: //www. flickr. com/photos/218977 7@N 00/2764057556>.

Works Cited § Colwell, Catharine H. , comp. "Mirror Equation. “ § § Online Physics Lab. Physics. LAB, n. d. Web. 26 Feb. 2011. <http: //dev. physicslab. org/Document. as px? doctype=3&filename=Geometric. Opt ics_Mirror. Equation. xml>. Kirkland, Kyle, and Sean M. Grady. "mirrors and lenses in optics. " Science Online. Facts On File, Inc. Web. 25 Feb. 2011. <http: //www. fofweb. com/activelink 2. asp? Item ID=WE 40&SID=5&i. Pin=STIFO 0005&Single Record=True>. Zitzewitz, Paul W. Physics Principles and Problems. New York: Glencoe, 2002. Print.