Thanks for your reply mfb. My reasoning behind the assumption is the following:
There are more than two energy levels in the atom.
If they are evenly spaced then the monochromatic pump can also cause transitions between the first excited and higher states (once first excited gets populated).
I...
Homework Statement
We will be considering an active medium that consists of atoms with four energy levels. These energy levels are the ground energy level E0 and three higher energy levels E1<E2<E3.
Consider the case where the onl radiative decay in this system occurs between levels E1 and E0...
its not so much about momentum but really about understanding the geometry of the problem.
You know that the water has a certain velocity, you know how far a single particle of water will travell in one second. You are also given the radius of the nozzle therefore you can easily figure out...