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Homework Help: Simple math im not understanding

  1. May 8, 2010 #1
    Heres the solution I have:

    220*10^-3=(6/4.9)(1-e^((-t*4.9)/(140*10^-3))
    e^(-4.9t/(140*10^-3))=08203
    t=5.658

    Could somebody expand this more for me please so I can see the mathematical operations to get to this solution?
     
  2. jcsd
  3. May 8, 2010 #2

    rock.freak667

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    Homework Helper

    Divide both sides by 6/4.9

    take ln of both sides of the equation
     
  4. May 8, 2010 #3
    When I divide 220*10^-3 I don't get the same answer.
     
  5. May 8, 2010 #4

    Borek

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    Staff: Mentor

    I got t=0.00566
     
  6. May 8, 2010 #5
    Shouldn't it be 220*10^-3/(6/4.9)=x
    lnx=lne^...
    lne^/lnx
    =ans??
     
  7. May 8, 2010 #6

    Borek

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    Staff: Mentor

    What is ln(ey)?
     
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