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Homework Help: A dust particle through an electric field

  1. Jan 26, 2014 #1
    1. The problem statement, all variables and given/known data
    A small piece of dust of mass m = 3.8 mu or micro g (micrograms) travels through an electric air cleaner in which the electric field is 526 N/C. The electric force on the dust particle is equal to the weight of the particle.

    (a) What is the charge on the dust particle?


    2. Relevant equations
    F=ma
    q=F/E


    3. The attempt at a solution
    ((3.8*10^-9)*9.81)/526=7.079*10^-11
     
  2. jcsd
  3. Jan 26, 2014 #2

    Curious3141

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    Homework Helper

    Two things: 1) no. of sig figs you can give the result to and 2) lack of units. Other than that, looks right. Is there a question?
     
  4. Jan 26, 2014 #3
    Okay, thanks! I just wanted to make sure I was doing it correctly.
     
  5. Jan 26, 2014 #4

    Simon Bridge

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    Science Advisor
    Homework Helper

    What he said.
    Always, please, show your reasoning and working.
    Always ask a specific question so we don't have to guess what you want.

    Oh... welcome to PF BTW.
     
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