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Homework Help: Uncertainty in radioactive half-life experiment

  1. Apr 5, 2012 #1
    1. The problem statement, all variables and given/known data

    I have conducted an experiment and found the gradient λ of a graph to be (2.15x10^-4) +- (0.15x10^-4)

    The graph being ln(A) i.e. the number of disintegrations/unit time - dN/dt against time t

    The half-life is
    T(1/2) = ln(2)/λ = -3223.9

    How do I find the uncertainty in the half-life?

    Thank you!

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Apr 5, 2012 #2
    I now realise that the % uncertainty in λ is 0.15/2.15 = 0.069

    Therefore multiply T(1/2) of -3223.9 by 0.069 which equals ±224.9, which is the uncertainty.

    3223.9 ± 224.9

    How do I correct this to take account of significant figures?
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