Solids Definition and 313 Threads

Also referring to the post by @Kostik plus answers, I'm wondering about surface charges of neutral solids such as metals or carbon, for example. I only want to discuss large scale effects so that the solid can be treated as continuous. The atomic structure is averaged out. I also assume that...

When two free jets collide at some impingement angle (not necessarily a head on collision), the usual assumption is that in the impingement zone there is a stagnation point around which stream lines are deflected. From this stagnation point, a thin liquid sheet is created, which eventually...

A spherical pressure vessel with a diamter of 10 m is tightly enclosed in a cylindrical containment vessel with the sphere just touching on all 4 sides . Additional protective material (assume is sand ) is added to the cyclinder to provide additional support .How much sand is required so that...

I am not sure, but below is my attempt. In solids the force between adjacent atoms/molecules is very strong. So, when a part of the solid medium is displaced perpendicular to the solid medium like a rope, the atoms/particles in the medium just ahead of the displaced part will tend to bring the...

Hi, I use the equation above to isolate N(x), I get ##N = -\int_0^x qdx## I don't know how to get the value of q. The dimensionnal analysis give me : ## q = \frac{\rho g S x}{L}##, but I'm not sure. Thanks for your help !

Hello, I am wondering why in all X-ray diffraction experiments used to probe or know the crystal structure of the solid they assume that the scattering process is elastic, e.g, if an X-ray with wave vector ##k\vec{n}## is incident on a sample, it will diffract with a wave vector ##k\vec{n}'## of...

This is a paragraph from Rev. Mod. Phys,82,1959(2010). From the article, I understand that Berry phase is gauge invariant only for closed loop evolution but what exactly is this evolution? Does it mean that the system initially start out with some Hamiltonian and I continuously change the...

Summary:: Need lecture notes for many body I want a lecture notes of a many body introduction course according to the book of "many body theory of solids" by John C.Inkson, Could anyone help me?

When I learned about Einstein solids in thermal physics, we assumed the fundamental assumption of statistical mechanics. For two interacting Einstein solids, I completely understand why this is valid after a considerable amount of time has passed. But, how can we model these solids as they get...

What are the types of thermodynamics processes that happen in solids or continuum medium

Hi all, Something I've been wondering - why don't two solid surfaces always stick together when touching each other? As far as I'm aware there are five basic types of solids: Atomic solids: Frozen noble gases containing single atoms held together by London dispersion forces. Molecular...

There is the equation: μ= Eu +Eg/2 +3/4kβTln(mu/mc) Eg is the band gap, but I don't understand what Eu stands for and how we can calculate it? Could it be the valence band?

Let ##_\Omega \left\{ (x,y,z)\in R^3 : - \sqrt{3-y^2-z^2} \leq x \leq z+2 ,y^2+z^2 \leq 3 \right\} ## and consider the function ##f(x,y,z)=y^2x+z^2x## Represent the domain ##\Omega## compute the vector field ##F=\nabla f## compute the inward flux. So I've found that one is a cylinder of...

I am uncertain if this belongs in the differential geometry thread because I don't know what area of mathematics my question belongs into begin with, but of the math threads on physics forums, this one seems like the most likely to be relevant. I recently watched a video by PBS infinite series...

I was introduced to the concepts like molarity, molality , mole fraction, formality, normality etc. during general chemistry and it was said that these concepts are used to measure the concentration of solutions. But as the thing called Chemical Equilibrium came I was surprised when I read "In...

I know that to find the volume under a surface and above a boundary we have to integrate twice. I can explain myself with an example :- Lets' consider that we need to find the volume under the surface z = \sqrt{1-x^2} and above the region bounded by y^2 = x and positive x-axis and x=5 ...

We always think in terms of isolated particles. It's better to analyze it with solids. If wave functions were just calculational tools. Molecules like the following still interact by wave functions, right? So how can it be calculational tool? And if it is, then what model do you use to...

Is there a relationship between the momentum operator matrix elements and the following: <φ|dH/dkx|ψ> where kx is the Bloch wave number such that if I have the latter calculated for the x direction as a matrix, I can get the momentum operator matrix elements from it?

Summary: How much weight can the bars support? Three one-meter-long bars with cross-section area A = 1 square centimeter support a rigid plate of weight W. For steel, E = 200 GPa and S = 400 MPa. Determine the maximum weight W the bars can support for three cases: (i) all three bars are...

With regards to the number of states available to the electrons in these solids. 1. a mass of polycrystalline iron (plenty of free electrons) 2. quartz (has practically no free electrons). 3. semiconductors Which of them has the most number of states available to the electrons? Which has...

The question will be formulated as a hypothetical question in classical physics. I will offer what I think is an answer using basic quantum mechanics. The classical question: Since it is the electrical repulsive force on the outer orbital elections, even with the inner orbital electrons serving...

I can understand how this applies to gases as in that scenario work done = pressure * change in volume and if change in volume is zero then W=0 so change in internal energy = Q. But I do not understand how this applies generally to all types of substances, say solid, liquid and gas.

We all know that the state of matter can be changed by increasing temperature or by applying pressure. And, all of these, in some way lead to a change in the particles' speed. The speed of the particle decides the state of matter. So, if we were to throw an object at very high speeds, like 50%...

Hi all, I've been for quite a while trying to identify this formula. dV / V = β ΔT - κ Δp where β is the thermal coefficient of volume expansion and κ is the isothermal compressibility. I think it's related to thermodynamics applied to solids and I can understand relations between the...

I see in most newer syllabus textbooks it says that diffusion is the mixing of fluids and diffusion cannot occur in solids But when is search the web I see lectures and books written on the title diffusion in solids and when I studied I was taught that diffusion occurs in solids but at very very...

Do electron minibands in quantum dot solids have a potential?

Why specific heat of solids and liquids doesn't change with change in temperature?

Hi all, I have trouble understanding some ideas relating to the Debye model. In my text (Oxford Solid State Basics by Steven Simon, page 11), it was stated that Debye wrote the following expression $$\langle E \rangle = 3\sum_{\vec{k}} \hbar \omega (\vec{k}) \ [ n_B (\beta \hbar \omega...

Hi all, I have a few questions related to Debye's model of solids. Any assistance is greatly appreciated. ##\textbf{1)}## My current understanding is that unlike Einstein's model, he views a 1D solid as a chain of atoms similar not unlike a 1D chain of masses coupled with springs. Thus a chain...

Hello, Wikipedia gave me prior hints as to how the speed of sound depends on viscosity but after searching on Google scholar and Google, I have yet to find any direct equations/findings that give a direct relationship of the speed of sound to the visocisty of fluids and solids outside of...

Hello! Does anyone have an idea of how can I obtain information from a band diagram about the directions along which the system conducts best and worst ? Thank you in advanced! :)

Why the velocity of longitudinal wave in solid is greater than transverse wave

Hello Can somebody explain for me what is the meaning of inversion symmetry in solids? and why does it breaks at the surface? and also why this inversion symmetry breaking leads to SOC(spin orbit coupling)? If somebody also know a document that explain this in full details(from A to Z) please...

why are molecular vibrations never synchronized in a way that would make them macroscopically observable?

I'm a bit confuse. In chapter 15, of Conceptual physics by Paul Hewitt: "Temperature is related to the random motion of atoms and molecules in a sub- stance. (...) More specifically, temperature is proportional to the average “trans- lational” kinetic energy of random molecular motion (motion...

Homework Statement I'm having some trouble with this problem as it seems my concept of the problem is completely wrong. Could someone look through my solutions and point out what I understood wrongly? Thanks in advance. Homework EquationsThe Attempt at a Solution a) 21 macrostates - this...

And if I can extend this further, for liquids?

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

α 1. Homework Statement The problem my question is about is 4. (iii). Second image First image is markscheme Homework EquationsThe Attempt at a Solution The CIE markscheme has h= 0.944 as the least possible value for h. They find this value for h by setting up an equation for the centre...

Is drawing of graphs of solids of revolutions important topic of mathematics? This makes me remerber conic sections topic. Conic sections topic belongs to algebra and drawing their graphs is important. So where does solids of revolutions belong to? I know calculation of their volumes belongs to...

According to Einstein (or Debay) model of solids, heat capacity drops exponentially at low temperatures: question is >> why it changes so dramatically at low temperature that is physical explanation of this?

I was cooking oats in water yesterday and the oats at the bottom of the pot got scorched. How is this possible? Doesn't the water smother the oats from oxygen?

question 1 The vector field F(x, y, z) = 2xi + 2yey2+z j +(ey2+z + cos z) k is conservative. Find a corresponding potential function. * e raise to power (Y square +z) Question 2 Consider a solid sphere of radius R, a cylindrical shell of outer radius R, inner radius a, and height h, and a...

I'm brainstorming ideas on how I could possibly create a sound proof box to block out the noise from my servo. I was thinking to create a plastic box with hollow walls that could be filled with some sort of liquid, not water, but maybe something with low viscosity to absorb the sound. Would...

For brittle substances can we say that elastic limit is equal to fracture stress ?

1. Find the centroids of the solids formed by rotating completely about the x-axis the plane regions defined by the following inequalities: (a) y^2 < 9x, y>0, x<1 (b) xy<4, y>0, 1<x<2 2. I used the equation for solids of revolution: Integral from a to b of (x[f(x)]^2.dx) / Integral from a to b...

I have a question about low pressure. So if i want to evaporate water from a pulverized product, but keep a solid substance intact (unknow solid, unknown properties, higher boiling point than water, but only slightly), should i do it with low (not too low) pressure? Will it remove more of the...

Homework Statement Hello! Here is the quote from the chemistry textbook by Tro: However, since carbon is a solid, its concentration is constant—it does not change. Adding more or less carbon to the reaction mixture does not change the concentration of carbon. The concentration of a solid...

Homework Statement A solid cylinder of uniform density of 0.85 g/cm3 floats in a glass of water tinted light blue by food coloring. https://s1.lite.msu.edu/res/msu/kashy/physicsLib02/32_Fluids1_Pascal_Arch/graphics/archimedes.gif Its circular surfaces are horizontal. What effect will the...