i have looked at this problem for over an hour and can't figure out how to do it.
The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 9%
per day. A sample of this radioactive substance has an initial mass of 3kg
. Find the mass of the sample after three days. Round your answer to two decimal places.
Note: This is a continuous exponential decay model.
And though the decay rate parameter is 9%
per day, the actual decay is not 9%
each day.
Best Answer
As the problem states, 9% the "decay rate parameter", not the daily decay rate. This problem is looking for use of the continuous decay formula, or $$P=P(0)e^{rt}$$In this particular problem, $$P=(3kg)e^{-.09*3}=2.29kg.$$