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Wondering about how heat from light will travel

  1. Nov 25, 2011 #1
    Let's say you take two metal objects, one black and one white. Out in the sun, the black will reach higher temperature in a given period of time.

    Now, let's say I take two glass jars. One is of DARK glass (like, an apple cider or wine bottle), and one is clear. In the clear one, I place several black pieces of metal, in the dark one, nothing. Then, I place something like water inside both containers.
    Which given amount of water will reach a higher temperature? The dark bottle will clearly absorb more than the clear one, but some of that heat will travel to the water. The rest will travel to the surrounding air. On the other hand, if one takes the clear container, the metal objects will absorb a large amount of heat and heat the water, and less will be dispersed to the atmosphere. Which method supplies the most heat to the water?
     
  2. jcsd
  3. Nov 25, 2011 #2

    DaveC426913

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    If you want to keep a building or car cool, do you put in clear glass or tinted glass?

    In the case of tinted glass, where does the bulk of the energy from the sunlight accumulate?
    In the case of clear glass, where does the bulk of the energy from the sunlight accumulate?
     
    Last edited: Nov 25, 2011
  4. Nov 25, 2011 #3
    So the clear one would result in a greater temperature increase?

    But since the jars allow light straight through, does that make a difference? I mean, the light needs something to focus off of to disperse any relevant heat...
     
  5. Nov 25, 2011 #4
    The clear glass/bottle would obiously collect a bit more heat, as DaveC426913 said do you put tinted or clear glass in your car? but other than that he provided your answer
     
  6. Nov 25, 2011 #5
    Well ... actually it depends on the sizes of the black metal pieces. If they are too small then the dark jar will collect more heat and conduct into the water inside than the dark metal pieces will collect and conduct into the water in the clear jar.
     
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