Question 610059
A lab has 50 mg sample of cobalt-60, which decays at the continuous yearly rate of 13%.
 A) Find a function R(t) that gives the number of mg present as a function of time in years.
R(t) = {{{50*(1-.13)^t}}}
:
B) How much of the sample will remain after 10 years?
R(10) = {{{50*(1-.13)^10}}}
put this in your calc
R(10) = 12.42 mg
:
C) What is the half-life of the element?
{{{50*(1-.13)^t}}} = 25
{{{.87^t}}} = {{{25/50}}}
using nat logs
{{{t*ln(.87) = ln(.5)}}}
:
t = {{{ln(.5)/ln(.87)}}}
t = 4.98 yrs, half-life