Question

Strontium 90 is a radioactive material that decays according to the function

Answer 1

Answer:

decay rate is 2.44% per year

after 40 years, 400*(e^-0.976)=150.73 gm

300=400(e^-0.0244t)

0.75=e^-0.0244t

 

ln both sides

-0.2877=-0.0244t

t=11.79 years

t (1/2) occurs when ln(0.5)=-0.0244t

t=28.41 years

Have a nice day!

Answer 2

Answer:

hey mate

the time required is 28.41 days