Physics

Problem

A detector records

640

disintegrations from a radioactive sample during the first

10\,\text{min}

and

512

disintegrations during the next

10\,\text{min}

. Assuming no material is added or removed, the half-life of the isotope is approximately a)

25\,\text{min}

31\,\text{min}

34.6\,\text{min}

15.5\,\text{min}