SOLUTION: 1. Plutonium has a half life of 24,000 years. Write an equation to represent the percentage of plutonium remaining after t years. P(t)= ___________ ____ 2. The intensity of ligh

Algebra ->  Equations -> SOLUTION: 1. Plutonium has a half life of 24,000 years. Write an equation to represent the percentage of plutonium remaining after t years. P(t)= ___________ ____ 2. The intensity of ligh      Log On


   

Question 723958: 1. Plutonium has a half life of 24,000 years. Write an equation to represent the percentage of plutonium remaining after t years. P(t)= ________________
2. The intensity of light below the surface of a particular lake is reduced by 10% for every metre below the surface. Write an exponential equation that models the percent of light left at any depth, x metres below the surface. L(x) =___________________
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
P%28t%29=P%5B0%5De%5E%28-kt%29
Find k first, using half life fact.

1%2F2=e%5E%28-k%2A24000%29
ln%281%2F2%29=-k%2A24000
-ln%281%2F2%29%2F24000=k
highlight%28k=2.888%2A10%5E%28-5%29%29
MODEL: highlight%28P%28t%29=P%5B0%5De%5E%28-2.89%2A10%5E%28-5%29%2At%29%29