Physics

Problem

The mean life of

^{137}\text{Cs}

44.0\,\text{years}

. A laboratory will need a sample with an activity of

3.7\,\text{kBq}

exactly

5.0\,\text{years}

from now. Calculate the number of

^{137}\text{Cs}

atoms that must be sealed in the source today. (Take

1\,\text{year}=365\,\text{days}