# Search results

1. ### Solid-state Physics: Fermi surface and necks in an FCC structure

Does anyone have some bibliography about necks in FCC structure Fermi surface? I have to solve this problem and I have no idea how to start. Thanks.
2. ### I 4th-rank isotropic tensor

I have this statement: Find the most general form of the fourth rank isotropic tensor. In order to do so: - Perform rotations in ## \pi ## around any of the axes. Note that to maintain isotropy conditions some elements must necessarily be null. - Using rotations in ## \pi / 2 ## analyze the...
3. ### Hamiltonian mechanics: phase diagram

The issue here is that I don't know how to operate the final equations in order to get the phase diagram. I suppose some things are held constant so I can get a known curve such as an ellipse. I attach the solved part, I don't know how to go on.
4. ### Lagrangian mechanics: central-force-like problem

I copy again the statement here: So, I think I solved parts a to c but I don't get part d. I couldn't even start it because I don't understand how to set the problem. I think it refers to some kind of motion like this one in the picture, so I'll have a maximum and a minimum r, and I can get...
5. ### D'Alembert's principle on a pulley system

This is the problem's picture: My problem is that what I got for one acceleration (m3's) via Newton's equations is not the same as via D'Alembert's principle (I've checked on my PC if they are the same expression). I can't find the mistake. Any suggestion is welcome. I attach pictures of what...