Question

Iodine 131 is a radioactive material that decays according to the function A(t)=A(sub0)e^-.087, where A(sub0) is the initial amount present and A is the amount present at time t(in years). Determine how long it takes for 250 grams of iodine 131 to decay 50 grams.
Choices:
a. 19 years
b. 5 years
c. 50 years
d. 10 years

Answer 1

U are in the wrong subject

Answer 2

this is a maths question^

Answer 3

Kinda but its still kinda physics

Answer 4

50=250e^(-0.87t)

Answer 5

solve by logs , easy

Answer 6

yes it is. you are trying to solve
\[50=250e^{-.087t}\] for t

Answer 7

-0.87t = ln(0.2)

Answer 8

\[\frac{1}{5}=e^{-.087t}\]

Answer 9

\[ln(.2)=-.087t\]
\[t=\frac{ln(.2)}{-.087}\]

Answer 10

i get 18.5 rounded. electeng in right too but i think maybe off by a decimal point if i read correctly

Answer 11

so im assuming 19

Answer 12

thanks