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27 Cards in this Set
- Front
- Back
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What is power?
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the rate of energy usage, which measures in units called watts.
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what are watts?
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A Power of one watt means an energy flow of 1 joule per second.
1 WATT = 1 JOULE |
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what is electro magnetic spectrum?
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the complete light, including radio waves, infrared lights, visible light, ultra violet light, X rays, and gamma rays.
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What is emission?
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A light bulb emits visible light, the energy of the light comes from electrical potential energy supplied to the light bulb.
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What is absorption?
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when you place your hand near an incandescent light bulb, your hand absorbs some of the light, and this absorb energy warms your hand.
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what is transmission?
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Some forms of matter, such as glass or air, transmit light, which means allowing it to pass through.
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What is reflection/scattering?
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Light can bounce from matter, leading to what we call reflection (when bouncing is all in the same general direction) or scattering ( when the bouncing is more random).
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What is wavelength?
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The distance from adjacent peaks (or through) waves.
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what is frequency?
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is the number of peaks passing by any point each second.
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What is Hertz?
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the standard unit of frequency of light waves; equivalent to unit of 1/s.
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what is speed?
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an rate at which an object moves. Its units are distance divided by time, such as m/s.
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Example:
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Suppose, a wavelength of 1cm and a frequency of 3 htz. The wavelength tell us that each time a peak passes by, the wavelength has travel 1 cm. the frequency tell us that 3 peaks pass by each second. therefore, the wavelength must be 3 cm/ s.
wavelength X frequency = speed |
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What is the speed of light?
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The speed at which light travels, which is about 300,000 km/s.
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What is Opaque?
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describes the material that absorbs light.
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what is scattering light?
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light that is reflected into random rirections.
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what is reflection?
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the process by which matter changes the direction of light.
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What is transparent?
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Describes a material that transmits light.
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What is photon?
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An individual particle of light, characterized by wavelength and frequency.
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What is electromagnetic radiation?
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another name for light of all types, from radio wavelengths through gamma rays.
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What is gamma rays?
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light with very shorts wavelengths (and hence high frequencies) shorter than those of X rays.
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what are X rays?
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light with wavelengths that fall of the portion of the electromagnetic spectrum between ultraviolet light and gamma rays.
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What is ultraviolet light?
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light with wavelengths that fall in the portion of the electromagnetic spectrum between visible light and X rays.
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What is visible light?
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the light our eyes can see , ranging in wavelength from about 400 to 700 nm.
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What is infrared light?
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light with wavelengths that fall in the portion of the electromagnetic spectrum between radio wavelengths and visible light.
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What is microwaves?
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light with wavelengths in the range of micrometers to millimeters.
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what are atom?
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consist of a nucleus made from protons and neutrons, surrounded by a cloud of electrons>
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what is an element?
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a substance made from individual atoms of a particular atomic number.
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