Assume that each decays according to the formula A(t)=A0ekt where A0 is the initial amount of the material and k is the decay constant.
Cobalt-60, used in food irradiation has a half-life of 4.6 years. If there is initially 148 grams present, find the following.
(a) The decay constant, k. Round your answer to four decimal places.
k= 34.31 Incorrect. Tries 1/99 Previous Tries
(b) Find a function A(t) for the amount of the isotope, A in grams which remains after time t in years.
A(t)= 6.90 Incorrect. Tries 1/99 Previous Tries
(c) Determine the time t in years for 90% of the material to decay. Round yours answer to two decimal places.
t= 40 years