Problema Solution

The function A= A0e^0.01386x models the amount in pounds of a particular radioactive material stored in a concrete vault. Where x is the number of years since the material was put into the vault. If 400 pounds of the material are initially put into the vault, how many pounds will be left after 120years?

Answer provided by our tutors

Ao = 400 lbs original amt 

x = 120 years of decay 

A = resulting amt

A = 400*e^(-0.01386*120)

A = 400*e^(-1.6632)

A = 75.81 lb

After 120 year there will be 75.81 lb radioactive material left.