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21 Cards in this Set
- Front
- Back
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Describe the a leeward breeze during the day.
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Because the land has a LOWER specific heat than water, it heats up faster and the air above it gets hot and rises toward the Sun. The cooler air over the ocean takes its place and so there is a clockwise breeze (convection current) and its a leeward breeze.
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Describe the a seaward breeze during the night.
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Because the land has a lower specific heat, it cools down faster, so the warmer air over the ocean actually rises and the cooler land air takes its place creating a convection current and a SEAWARD breeze.
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Explain the greenhouse effect.
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High energy UV gets into earth but the infrared radiation is blocked by the clouds and stays in the ozone and makes the earth hotter because it cannot escape.
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Why do cities by deserts have different climates than those by water?
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Desert cities have no water in the air/soil and because the land has a low specific heat, they heat up AND cool down very fast. Cities by water get their weather from west to east so some of the air above the water (with a high specific heat and thus not as hot/cold) goes to the land and gives it a less extreme climate.
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Explain the process of cloud formation.
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On earth there is high temp/pressure and so water evaporates and rises. Up higher, the temp/pressure are lower so the clouds expand, cool, and condensate (at the thermocline). As they are moving slower, the water molecules attach to each other and clouds form in the air.
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Why do lakes freeze from the top down?
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When a cool breeze goes over a lake, the water cools until it gets to 4C, where it is most dense. The 4C water sinks to the bottom, where it is followed by 3C, 2C, and so on until the least dense frozen ice is at the top at 0C.
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Why does hot water freeze faster than cold water?
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Because hotter water evaporates faster, which is a COOLING process, so it loses 540 more calories and loses heat faster, and this freezes faster than cold water.
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How does a pressure cooker make temps hotter than 100C possible?
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Because it loses as much heat at it gains, more pressure means the molecules compress, which means even more temp, and while only a little heat escapes, the pressure cooker continues to heat up past 100C.
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How does a boiler work?
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The chemical energy in coal is burned to make thermal energy. Thermal energy (steam) in boiler turns turbine to make mechanical energy. Mechanical energy of turbine turns generator to make electrical energy and turn on lights, etc.
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Which equation do you use for a phase change from water to steam?
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ΔQ = mLv
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Which equation do you use for water to ice?
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ΔQ = mLf
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Which equation do you use for no phase change at all?
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ΔQ = mcΔT
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What is the specific heat if ice and steam?
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.5, not one.
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Do you use negative values in the long heat of vap/fusion problems?
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No, only in the short, simple ones.
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Describe how a refrigerator works.
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Refrigerators compress freon causing it to condense on outside coils and expand (Evaporate) it on inside. Expanded and evaporated gas cools (absorbs heat from food) and is transferred outside where gas is condensed by the compressor, causing it to heat and transfers the heat to the room.
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How do you know when to use ΔL or ΔV?
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Whether you're given the linear or the volumetric expansion coefficient.
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Describe the formation of fog.
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Fog appears when moist air cools and condenses over land. Usually warmer air from over bodies of water is picked up and blown over to land where it cools and condenses to form fog.
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Why is temperature proportional to the AVERAGE kinetic energy of molecules but not the total kinetic energy?
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Because then, an ice cold lake would have a higher temp than a boiling cup of coffee.
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Why are expansion joints placed in bridges, roads, and sidewalks?
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So that cracking due to expansion won't occur.
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Explain how a combustion engine works.
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Spark plug ignites gasoline inside a cylinder (chemical to thermal energy). Heat will expand gas and push down a piston. The piston turns a crankshaft and then pushes gas out the exhaust pipe. Crankshaft turns the driveshaft, wheels, blades.
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Why is it harder to freeze deeper lakes?
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Because all the water must be cooled to 4C before the lake can freeze and the winter is usually not long enough to do this.
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