Raymond B. answered • 04/16/21
Tutor
5
(2)
Math, microeconomics or criminal justice
t=0 x=100
t=100 x =2
when is x=50% that's the half life
50,25,12.5,6.25, 3.125, 1.5625, 6 half lives leads to 1.6 %
100/6 =about 17 days
in 17 days, down to 50
34 days 25
51 days 12.5
68 days 6.25
85 days 3.1
102 days 1.6
half life is about 17 days
18 days reaches 96 days with down only to 3.1%
half life is between 17 and 18 days
P=Ae^-rt
.02 =e^-rt
ln.02=-0.3912 =-rt
rt =0.3912 for t=100 days
100r = 0.3912
r =.3912/100
A/2 =Ae^-rt where t= days for half life
1/2 = e^-rt
ln.5 =-.693 = -rt =-.03912t
t =.693/.03912 = 17.715 days for half life= about 17 days & 17 hours
