Question

6.8.21 E Oestion Help A days) is safe to feed the haylocows when 15% of t the release of radioactive material in the atmosphere from a nuclear power plant in a country in 1981, the hay in that country was contaminated by a radioactive isotope the radioactive scope romains how long did the farmers need to wait to use this hay? d ays for t he sale to feed the hay to the cows The farmers needed to wait approxima Round to decimal places needed)

Answer 1

21.9 days

Standard equinon for radioactive decay is net ACD= toe balfile here Alt)= amount radio achve material after a t time o is initial amount of radio alaue Substance given it is convenient to have is n ot Initial toradioactive substance to sto or less to start feeding. so A(U)= 15.= 0.15 AO find t for this one at: 0.15 AO = A e 8 2 19®nt6.15 no 0.is take natural log on both sione t = In o.15 we know the to -In (2) xt = hois t = 8 60.5) -21.8957 -In (2) ~21.9 21.9 days &