Help Me Decipher: Radio-nuclide in Blood Volume

[Reshma]

Someone first of all someone help me decipher this question.

A small amount of solution containing Na²⁴ radio-nuclide with activity A₀ = 2 x 10³ disintegrations per second was injected in the bloodstream of a man. The activity of 1.0cc of blood sample, taken 5 hours later, turned out to be A = 16 disintegrations per minute per cc. The half-life of the radio nuclide is T = 15hrs. Find the total volume of the man's blood.

 

[daveb]

If you set the volume of blood to be V, then the inital concentration is A_0 over V, and the final concentration is given. You should be able to find V by back decaying the final concentration.

Does that help?