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23 Cards in this Set
- Front
- Back
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Light
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range of frequencies of electromagnetic waves that stimulates the retina of the eye, travel in a straight line in a vacuum or other uniform medium
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Light waves have wavelengths from...?
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400 nm to 700nm, shortest wavelength are seen as violet
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Ray model
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ignores "wave" nature of light, useful to describ ehow light is reflected or refracted
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Speed of light
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299,792,458 m/s or 3.00 x 10^8 m/s, thought light was instantaneous, late 1600's--found light has a finite speed, early 1900's--speed of light 2.997996 plus or minus 0.00004 x 10^8 m/s but really light is the number above
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luminous body
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emits light, ex: light bulb
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illuminate body
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reflects light produced by an outside source, ex: apple, pink car, blue sweater
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luminous flux (p)
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measures total output of light source, unit=LUMENS (lm)
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illuminance (e)
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illumination on a surface, measured by lm/m^2 or lux(lx)
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luminous intensity
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some light sources are measured by "CANDELA" (cd) or candle power, this is a measure of luminous intensity
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inverse-square relationship
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further away the surface is=more spread out the light will be on surface aka DIMMER
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transparent
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materials transmit light waves without distorting images
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translucent
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materials that transmit light but do not permit objects to be seen clearly through them
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opaque
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transmit no light but absorb or relfect all light incident upon them
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spectrum
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ordered arrangement of wavelengths
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primary colors
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red, green, blue light
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secondary colors
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yellow, cyan, magenta
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complementary colors
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two colors of light which when added together produce white light
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pigment
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a colored material that absorbs certain colors and reflects/transmit other colors
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primary pigment
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a pigment that absorbs only one color from white light
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secondary pigment
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a pigment that absorbs two primary colors from white light and reflects one
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thin film interference
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result of constructive and destructive interference of light waves
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polarized
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half the light passes through and the intensity of that light is reduced by half
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dye
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a molecule that absorbs some light wavelengths and reflects or transmits others
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