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11 Cards in this Set
- Front
- Back
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The transfer of thermal energy through space from the Sun to the Earth is by |
Infra Red
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Infra-red radiation is absorbed, reflected and emitted to different extents by different surfaces. Which of the following statements best applies to dark, matt surfaces A They are good emitters of infra-red radiation. B They are good reflectors of infra-red radiation. C They are poor absorbers of infra-red radiation. D They are poor emitters of infra-red radiation |
A They are good emitters of infra red radiation
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Solar panels use the suns infra-red radiation to heat water. They are painted black – why
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To absorb more infra-red radiation
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African Elephants have bigger ears than Indian elephants – why? |
Larger surface area to increase heat loss
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Why do liquids cool down as they evaporate?
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Evaporating molecules are the most energetic, meaning the average energy drops after they have left
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What can be done to speed up the rate at which liquids evaporate?
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Larger surface area, higher temperature, wind |
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Why are fridges almost universally white? |
White is a poor absorber of infra red, making the fridge cooler
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A fridge freezer is in a room of temperature 20 degrees, the fridge is at 5 degrees and the freezer at -18 degrees. Which will have the faster heat transfer?
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The freezer – bigger difference in temperature
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What does specific heat capacity mean? |
How much energy is required to raise the temperature of 1kg of a material by 1 degree |
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How much energy is required to raise 2 kilograms of water (c = 7200 J/KgoC) by 20oC? |
288000J |
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When purchasing double glazing would you want windows with a high or a low U-Value? |
Low u-value
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