Groove Salad

Wow. I have spent three hours, non-stop, writing up my Quantum Mechanics 2 problems in clean paper. It has been made a short time thanks to SomaFM's Groove Salad. It is an Internet radio station, like they say, "a nicely chilled plate of ambient beats and grooves". So far the only problem that I am doubtful is one about partial wave’s phases. I am getting complex numbers for them. Maybe my approximations are incorrect, or these complex numbers can have some physical interpretation. I guess after I finish with QM 2 I will start writing up the problems for Advanced Quantum Mechanics. These ones are only three. Again, I have a doubt on one of them: What the hell does "Center of Mass Energy" means?