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Why do dust particles stay suspended in the gas?

  1. Oct 26, 2008 #1
    A diagram shows many very small dust particles suspended in the gas in a closed transparent glass.

    Question: Explain why dust particles stay suspended in the gas and do not fall to the bottom of the syringe.

    My answer:
    Dust particles are constantly being bombarded by free moving gas molecules in the glass that causes it to counteract the force of gravity. Therefore, the dust particles stay suspended because the resultant force acting on the dust particle is zero.

    Am I correct in explaining this phenomenon? Please correct me.
  2. jcsd
  3. Feb 21, 2009 #2
    That sounds good and just like the gas molecules the dust particles will be moving randomly(Brownian motion)
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