A sample of 200 grams of radioactive substance decays according to the function $\mathrm { A } ( \mathrm { t } ) = 200 \mathrm { e } ^ { - 0.031 \mathrm { t } }$ where t is the time in years. How much of the substance will be left in the sample after 40 years? Round your answer to the
Nearest whole gram.
A) 1 gram
B) 2465 grams
C) 58 grams
D) 0 grams

Question

Quizplus · Accepted Answer

To find the amount of substance left after 40 years, substitute $t = 40$ into the decay function: $A(40) = 200e^{-0.031 \times 40}$. Calculating this gives approximately 58 grams.

A Sample of 200 Grams of Radioactive Substance Decays According A(t)=200e−0.031t\mathrm { A } ( \mathrm { t } ) = 200 \mathrm { e } ^ { - 0.031 \mathrm { t } }A(t)=200e−0.031t

A Sample of 200 Grams of Radioactive Substance Decays According $\mathrm { A } ( \mathrm { t } ) = 200 \mathrm { e } ^ { - 0.031 \mathrm { t } }$