if the half-life is k years, then
y = 100(1/2)^(t/k)
since y(20) = 80,
100(1/2)^(20/k) = 80
k = 62.126
A certain radioactive material is known to decay at a rate proportional to the
amount present. A block of this material originally having a mass of 100 grams is observed after 20 years to have a mass of only 80 grams. Find the half-life of this radioactive material. (Recall that the half-life is the length of time required for the material to be reduced by a half.)
A. 59.030 years
B. 61.045 years
C. 54.343 years
D. 56.442 years
E. 62.126 years
2 answers
Plz dont cheat and use this website
4 answers