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A 45 gram sample of a substance that’s used to preserve fruit and vetgetables has k- value of 0.1109

User Nell
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What If a 45 gram sample of a substance that's used for drug research has a k-value of 0.1325???????


User Joel Larson
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The decay formula is
N(t) = N₀ exp(-kt)
where
N₀ = 45 g, original mass
N(t) = mass after time t, days
k = 0.1109, the decay constant.

At half life, N(t) = (1/2)*N₀. Therefore
1/2 = exp(-0.1109t)
Take natural log of each side.
ln(0.5) = -0.1109t

t = ln(0.5)/(-0.1109) = 6.25

Answer: 6.3 days (nearest tenth)

User Rafaelpadu
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