Question

Plutonium-240 decays according to the function Q(t) = Qoe^-kt

Answer 1

Answer:

  9990 years

Step-by-step explanation:

The exponential function with given values filled in can be solved for the unknown using logarithms.

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  Q(t) = 12 = 36e^(-0.00011t)

  1/3 = e^(-0.00011t) . . . . . . divide by 36

  ln(1/3) = -0.00011t . . . . . . take natural logs

  t = ln(1/3)/(-0.00011) . . . . divide by the coefficient of t

  t ≈ 9990 . . . years