Term
| Energy transfer by heating |
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Definition
•3 methods – conduction, convection, radiation
•The bigger the temperature difference between an object and its surroundings, the faster the rate at which energy is transferred by heating.
•Rate of transfer of energy depends on surface area and volume, object materials, surfaces.
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Term
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Definition
•All objects emit and absorb infrared
•The hotter an object is, the more IR it emits in a given time(time is important!)
•Dark, matt surfaces – good absorbers, good emitters (this means that a dark, matt object will heat up faster or cool down faster than a light, shiny one)
•Light, shiny surfaces – poor absorbers, poor emitters, good reflectors.
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Term
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Definition
Conduction, convection, evaporation and condensation all transfer energy, and all involve particles in their theories.
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Definition
In an object, the more kinetic energy the particles have, the hotter the object is.
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Term
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Definition
Convection Takes place in liquids and gases. When a liquid or gas gets hotter, the particles have more KE à they move around more, making the liquid or gas less dense. Therefore, hot liquids or gases will rise above cooler liquids or gases. (HEAT DOES NOT RISE, HOT LIQUIDS AND GASES DO!!)
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Term
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Definition
Conduction
All to do with particles banging into each other and passing on KE. Metals have free electrons which can also pass on KE, making metals excellent conductors. The arrangement of particles in a substance determine how good a conductor it is.
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Term
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Definition
Particle arrangements:
Solid – fixed in place, least amount of KE but still some movement
Liquid – some fixed arrangement, free to slide over each other, more KE than solid
Gas – free to move about randomly, no fixed arrangement, lots of KE
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