EDT 181 Exam#3 Review

EDT 181 Exam#3 Review - EDT 181 Exam #3 Review I. Chapter...

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EDT 181 Exam #3 Review I. Chapter 7: Light A. Sources of Light Luminous= when something produces light Incandescent= when visible light is given off as a result of high temperatures o The moon and planets shine by reflected light, not luminous Electromagnetic Wave Model= Describes the relationship between electricity, magnetism, and light o The frequency of an electromagnetic wave depends on the acceleration of the charge Blackbody Radiation= Electromagnetic radiation is given off from matter at ANY temperature B. Properties of Light Light Ray Model= Describes the travel of light in a straight-line path. The light ray is a line that is drawn to represent the straight-line travel of light. Represents law of reflection (mirror) and law of refraction (lens) C. Light Interacts with Matter 1) Smoothness of surface, 2) nature of the material, 3) angle at which light ray strikes the surface Perfectly Smooth= reflection, Not Smooth= diffuse reflection Transparent= materials that allow transmission of light through them Opaque = Do not allow transmission of any light. They reflect light; absorb light, and partly reflect/absorb light. Absorbed light gives up its energy to the material and may be reemitted at a different wavelength and temperature increase. Light that interacts with matter is reflected, transmitted, or absorbed, and all combinations are possible Materials are usually characterized by which of these interactions they mostly do, but doesn’t mean that other interactions aren’t occurring D. Reflection Incident Ray= An incoming ray. A line representing an original ray from the tree Normal Ray= Reference line that is perpendicular to the reflected surface located where the incident ray hit the surface o Angle of Incidence (Between Incident and Normal = Angle of Reflection (Between Normal and Reflected) o Curved mirrors are concave with center curved in, and convex with center bulging out E. Refraction The change of direction of a light ray at the boundary Refracted Ray= new direction of travel o When light moves from one transparent material to another with a SLOWER speed of light, the ray is refracted toward the

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normal. If light moves FASTER, the ray is refracted away from the normal F. Dispersion and Color The speed of electromagnetic waves is related to the wavelength and the frequency by: C= wavelength x frequency Colors= red (refracted least, sunset), orange, yellow, green, blue, and violet (refracted most, blue sky) G. Interference Light from one source is used to produce two breams of light that are in-phase (having crests-troughs together as they move away from source) Only explained by waves. Ex) young’s two slit experiment Interference Pattern= Pattern of bright lines and dark zones. Constructive
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This note was uploaded on 11/15/2011 for the course EDT 181 taught by Professor Keithstevenharring during the Fall '08 term at Miami University.

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EDT 181 Exam#3 Review - EDT 181 Exam #3 Review I. Chapter...

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