Question

3.

Radium radioactively decays according to the
function
-0.004
R(t)=Roe
where Ro is the original sample amount and
R(t) is the final amount remaining after 1 years.
Beginning with a 14 mg sample, how much
remains after 10 years?
(A) 13.45 mg
(B) 14.75 mg
(C) -1.52 mg
(D) 13.94 mg
(E) None of the above

Answer 1

If
`R(t)=R_0e^(-0.004t)` and
`R_0=14` and
`t=10`,

then
`R(10)=14e^(-0.004\cdot10)\approx 13.45`

A.