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Unformal question about molecules of gases

  1. Nov 21, 2008 #1


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    In high school I've been told that the molecules of gases have generally speed of severals kilometers per second. Hence why the wind is not always present, and why not that fast? (I guess it has to see with the huge number of particles... I never studied such a system in Physics yet, I believe but I might be wrong.)
    Also why when I open a bottle of perfume I cannot smell its odor if I'm at say 2 meters from it? (It's like the big molecules of perfume cannot move that fast at all since there are too much other molecules or so).
    P.S.: I've asked this question to my teacher when I was younger and it seems he misunderstood the question. Answering that the wind was a depression or something like that. Which do not say why the wind is not as fast as most molecules in air so most molecules forming the wind itself.
  2. jcsd
  3. Nov 21, 2008 #2


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    Essentially, the gas molecules are moving in a chaotic pattern so it takes longer for them (e.g. "perfume molecules") to diffuse through the air and to your nose.

    Wind develops as a result of pressure or temperature differences between two locations on the Earth's surface.

  4. Nov 22, 2008 #3


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    Thank you stewartcs, I get it.
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