Question 681906

{{{A(t) = 30e^ -.001t }}}


{{{A=A[0]e^(-lambda*t)}}}..........lambda=λ{{{t}}}


where:

{{{A[0]}}}= the {{{initial}}} activity

{{{A}}} = the activity at time, {{{t}}}



1. How much material was present initially ?

{{{A[0]=30}}}

2. How much will be present in 2000 years ?

if  {{{t=2000}}}

{{{A(2000)= 30e^(-.001*2000)}}}


{{{A(2000) = 30e^ -2 }}}


{{{A(2000) = 30(1/e^2) }}}..............{{{e=2.718}}}


{{{A(2000) = 30/7.387524 }}}


{{{A(2000) = 4.0609005128105167577120561638785 }}}


{{{A(2000) = 4.06 }}}