1. ### Formula for fictitious moments

Hi All, Everyone knows so called "fictitious" forces, also known as "inertial" forces. They are forces felt by some mass point placed in a non-inertial frame. For example: a ball in a moving car or in a carousel. Maybe most intuitive fictitious forces are centrifugal forces, but there are also...
2. ### A Mott insulators and electron-electron insulators

I found this paragraph from one of wiki article, "Mott considers a lattice model with just one electron per site. Without taking the interaction into account, each site could be occupied by two electrons, one with spin up and one with spin down. Due to the interaction the electrons would then...
3. ### Crystal Symmetry Problem

Hello guys! I have to solve a problem about crystal symmetry, but I am very lost, so I wonder if anyone could guide me. The problem is the following: Using semiclassical transport theory the conductivity tensor can be defined as: σ(k)=e^2·t·v_a(k)·v_b(k) Where e is the electron charge, t...
4. M

### Solids with different sound velocity at diffrent tempratures

i work on phononic crystals and i want to find solids with diffrent sound velocities and mass density in diffrent temprature i can just find BST but i need more matherials please help me my friends best regards
5. ### Comsol Help -- How to Enable Rotating?

Hi, I'm a newbie at Comsol and want ask for guide how to fill something with fluid and make sphere rotate. My goal in creating system where one sphere contains second. Second sphere rotates on its axis. Volume between is filled with fluid. I understand how to create spheres, but couldn't...
6. ### Why do atoms in a solid act like hard balls?

Homework Statement Why can we assume that atoms in a solid material act like hard balls? The Attempt at a Solution because they are tightly packed together when in a solid state[/B]
7. ### Thermodynamics of hyperelastic solid

Can someone please help with hyperelastic theory, I need to know how changes in reversible work are related to energy density function and then to strain and stress tensors. A reference that explains the theories simply would also be appreciated. So far I have failed to find anything relatively...
8. ### Volume of a solid bound by four surfaces

Homework Statement Compute the volume of the solid bounded by the four surfaces x+z=1,x+z=−1,z=1−y2,z=y2−1 Homework Equations Fubini's theorem? The Attempt at a Solution I have tried to visualize this solid and define the limits; when I attempted to integrate by dxdzdy (in that order), I set...
9. ### Interpreting Kinetic Temperature for Solids / Liquids

Hi all, I'm brushing up on some thermodynamics, and having been reading up on the interpretation of temperature as derived from kinetic theory. I can follow the derivation for an ideal, monatomic gas which relates temperature to the average, translational kinetic energy of the molecules. Most...
10. ### Solid electron wavefunction localization vs delocalization

In a solid, is electron's wavefunciton confined to a molecular orbital between atoms or is it delocalized and extends over the volume? According to valence bond theory, electrons are localized in bonds between atoms. But according to band theory (or Bloch wavefunctions), electrons are...
11. ### Emission Spectrum of Solids

Hi all, I've got two questions about the emissions spectrum from solids. Question #1: I feel like I have a reasonable understanding of line absorption and emission spectrum of low density gases based on transitions of electrons between discrete allowed energy levels in a gas. I'm trying to...