Doctors use radioactive iodine as a tracer in diagnosing certain thyroid gland disorders. This type of iodine decays in such a way that the mass remaining after

Question

m(t) = 6e^−0.087t

where m(t) is measured in grams.

 

a) Find the initial mass (mass at time t = 0).

 

b) How much of the mass remains after 20 days?

 

Answer 1

m(t) = 6e^-0.087t

 

You did not state the units of t.  I will assume t = days.

 

(a)

 

m(0) = 6e⁰ g = 6 g

 

(b)

 

m(20) = 6e^-0.087(20) g ≅ 1.053 g