SOLUTION: A sample of 800 grams of radioactive substance decays according to the function A(t)=800e^-0.028t, where t is the time in years . How much of the substance will be left in the samp

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: A sample of 800 grams of radioactive substance decays according to the function A(t)=800e^-0.028t, where t is the time in years . How much of the substance will be left in the samp      Log On


   

Question 725094: A sample of 800 grams of radioactive substance decays according to the function A(t)=800e^-0.028t, where t is the time in years . How much of the substance will be left in the sample after 10 years? Round to the nearest whole gram.
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
Just replace the t with 10 and enter it into your calculator. If your calculator has buttons for parentheses and for the number e, you could enter the whole expression at once:
800*(e^(-0.028*10))

If there is no button for "e" then use ln^(-1)(1) or 2.7182818284590452353602874713527 (or a rounded off version of this).

If there are no buttons for parentheses then raise e to the -0.28 power (since (-0.028 * 10 = -0.28) and then multiply by 800.

And last, round the answer you get to the nearest whole number.