SOLUTION: The half-life of a substance is 3.2 minutes. What percent of a sample remains after 10 minutes?

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: The half-life of a substance is 3.2 minutes. What percent of a sample remains after 10 minutes?      Log On


   

Question 1062588: The half-life of a substance is 3.2 minutes. What percent of a sample remains after 10 minutes?
Answer by josgarithmetic(39615) About Me  (Show Source):
You can put this solution on YOUR website!
y=p%2Ae%5E%28-kt%29

1%2F2=1%2Ae%5E%28-k%2A3.2%29
ln%281%2F2%29=ln%28e%5E%28-3.2k%29%29
ln%281%2F2%29=-3.2k
ln%282%29=3.2k
highlight_green%28k=ln%282%29%2F3.2%29





t=10.

y=1%2Ae%5E%28-%28ln%282%29%2F3.2%29%2A10%29

y=e%5E%28-ln%282%29%2A10%2F3.2%29

y=0.1146

11.5% sample remains after 10 minutes.