Question

After the release of radioactive material into the atmosphere from a nuclear power plant in a country in 1987. the hay in that country was contaminated by a radioactive isotope (half-life 8 days). If it is safe to feed the hay to cows when 12% of the radioactive isotope remains how long did the farmers need to wait to use this hay? The farmers needed to wait approximately days for it to be safe to feed the hay to the cows. (Round to one decimal place as needed.)

Answer 1

t 8 0.12 est - of In both side t In (0.5) = ln (0.12) 8 t = In 20.12) In(0.5) t = 24. 47 t 25 days Absues your rating is important - Theme

let initial & Solyn - quantity of radioactive material into the atmosphere = ao half life = 8 days el ao after 8 day quantity so function of remainning quantity a(t) = Oo a Do = 90 6=t So Q (+)- A. (a)" after b = 8 days Q (8)= a. 2 ho - a (0) a= (5) 2 1/8 So O() = 9. (+) 8 So let far mes need to wait t days so 0(t) = 12% of 9= 0-149. = Q (H) 0.129