SOLUTION: A radioactive substance is known to decay at a rate proportional to the amount present. If half of a given sample has disappeared after 1200 years, find ( to the nearest percent)

Question 1077704: A radioactive substance is known to decay at a rate proportional to the amount
present. If half of a given sample has disappeared after 1200 years, find ( to the
nearest percent) what percentage remains after 1800 years.
Answer by jorel1380(3719) (Show Source): You can put this solution on YOUR website!
Half the mass lost is:
1/2=e^-kt where k is a constant, and t is the time. In this case,our substances' half life is 1200, so:
-0.69314718055994530941723212145818=-1200k
k=0.000577622650466621
e^-(0.0005776226504666211)1800=35.355339059327375658806198307235% of the mass remaining after 1800 years. ☺☺☺☺
RELATED QUESTIONS
A standard measurement of the speed at which a radioactive substance decays is its half... (answered by ewatrrr)

8. Radioactive materials like uranium follow the law of uninhibited decay, which is an... (answered by josgarithmetic)

The mass of a radioactive substance follows a continuous exponential decay model, with a... (answered by ankor@dixie-net.com)

A certain radioactive isotope has a half-life of approximately 1300 milliseconds. How... (answered by nerdybill)

Use the exponential decay equation, where A is the amount of a radioactive material... (answered by ankor@dixie-net.com)

A=A0e^-0.5t is the equation that gives the decay of a radioactive substance. the amount... (answered by nerdybill)

The mass of a radioactive substance follows a continuous exponential decay model, with a... (answered by josgarithmetic)

The half-life of a radioactive substance is the time it takes for half of the substance... (answered by ankor@dixie-net.com)