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I have a few doubts about this problem. So we have two charged spheres of radius $r_1$ and $r_2$, one is initially charged with a charge $Q$, while the other one is initially without charge. The problem has a lot of questions that I already solved and I don't have any doubts about that. However, I still have one questi... |
in a wire with current :
$$
R = \int_a^b E dl / \int_\ ^\ j ds\
$$
$$ R=EL/jA
$$
Why E consider to be constant. even if I say V is constant between a,b can not assume E is constant , it is constant to t not to L
|
Shoud the total energy of a particle$($kinetic energy $+$ potential energy$)$ increase when positive work is done on that particle?
If the answer is yes, then why the total energy does not increase when work is done on a falling object by gravitational force?
|
We know that there can be possible higher derivative corrections (stringy corrections) to the Einstein-Hilbert action. In GR, to ensure that we get the Einstein Field equations from varying the E-H action, we necessarily have to add the Gibbons-Hawking-York boundary term (Wikipedia link to GHY), as well as a counterter... |
I am not a physicist but I've started studying the subject and noticed that terms like "random", "randomness", "randomly" are widely used when talking about nature. For example, random movement of atoms, random fluctuations, random path of an electron etc.
My question does not concern any of these examples themselves. ... |
I was watching this simulation of two quantum wave packets colliding in a box:
https://physics.weber.edu/schroeder/software/CollidingPackets.html
The wave function gets arbitrarily delocalized as time goes on until you have almost an equal probability of finding the two particles anywhere in the box. This would mean th... |
Can you explain me why in the pair production process we need a minimum energy $E_\gamma=2m_e$ in terms of invariant mass?
I tried to calculate it but I get another result like $E_\gamma=2m_e+\frac{2m_e^2}{m_N}$ where $N$ is the nucleus.
|
I'm recently taught that the angle of diffraction of waves depends on the barrier width relative to the wavelength. For example, if you have a plane wave of shorter wavelength, and if it hits a gap of an obstacle, the angle of diffraction will be smaller since the gap is bigger compared to the wavelength, and vice vers... |
I accidentally fell a water droplet on my mobile phone's screen. But on observing closely I saw that the water droplets showed rainbow colors (the screen was mostly white). By rainbow colors I mean that; on slowly shifting my sight I could see the colors changing and were from the white light spectrum. Can somebody exp... |
Imagine there is a table. then put a very heavy object, that breaks the surface. does the table react as much as the force that the object's given to it or it doesn't? how is it?
|
Let's suppose a theoretical case where a car doesn't start with rest but with a high velocity enough to kill a man. The car doesn't change it's velocity i.e no acceleration or deceleration and hits a man after a while(Assume car is moving on straight path). Since, velocity is constant, acceleration is zero. So is the f... |
I've been studying "Lifetime of a quasiparticle in an electron liquid", by Qian and Vignale. Much of it makes sense, but there is a detail in the calculation of the exchange term that doesn't make sense to me. Eqn. 23 gives
$$\frac{2\pi me^2 }{pqk_s\sqrt{k_s^2+4k_F^2-q^2}} $$
This follows from Eqn. 69 in the appendix ... |
Reference:
Chapter 11.3.1 of Freedman and Van Proeyen's Supergravity textbook.
\begin{eqnarray}
\notag
\delta(a,\lambda) \phi(x) &=& \left(a^\mu(x) P_\mu -\frac{1}{2}\lambda^{\mu\nu}(x)M_{\mu\nu}\right) \phi(x) \\\notag
&=& \left(a^\mu(x) \partial_\mu +\lambda^{\mu\nu}(x) x_\nu \partial_\mu\right) \phi(x)\\\notag
&=& ... |
I'm trying to define if the scattering $u\bar{d} \rightarrow c\bar{b}$ is possible in any of the fundamental interactions, I know that in QCD (channel t) is allowed because of the charge conservation, but I'm not sure if the gluon can change the flavor of the quark u into the c quark. The same thing happens with the ch... |
A while back, I asked a question about the absorption of different wavelengths by matter (see this post). I received some excellent answers that prompted to undertake some more in-depth research, especially concerning band structures / energy bands in materials. I did this and have a better understanding of this topic ... |
I'm having quite a hard time getting why we consider $I=0$ in some steady volume with nothing changing over time (because what comes in, comes out from my poor understanding).
If we do have some changes over time, why do we say $I=-\frac{dQ}{dt}$, with a minus? Considering current as a flux seems very non-intuitive for... |
Of a combustion engine, the speed, torque, and power is measured at the crankshaft.
For a measured pair of values for speed $N$ and torque $M$, can there be more than one value for power $P$? In other words, is the power defined by the torque and speed?
There are opinions trying to convince me that it depends on the en... |
If I assume only 1-dimensional space i.e. every event is defined by just 2 space-time co-ordinates $(x,t)$
Can I derive the Lorentz Transformation in this setup?
Only condition I can use in 1-D setup is that light beam travelling in $+ve$ $x$-axis and $-ve$ $x$-axis will both have same speed '$c$' in both the inertial ... |
what force throw to the wall is applied in this situation?
what force does this wood is importing to the wall that makes the normal force?
|
The equation trying to prove that Wick's theorem by induction in P&S on page 90 implies that normal ordering can be moved outside a commutator (at least with a positive frequency field), which I just don't understand. It implies
$$[\phi_1^+,N(\phi_2\ldots\phi_m)] = N([\phi_1^+, \phi_2\ldots\phi_m]).$$
What am I missin... |
Assume a wire is 5 m long and we want to find how much force is required for increasing the length of it 5 m and make it 10 m long.
$$F = \frac{YAl}{L}\, .$$
If Y=5 and A=1 we will find the answer 5. But if we calculate it by parts the calculation doesn't match.
If we calculate how much force is required for increasing... |
A Spins one wheel of an upturned bicycle, mud particles fly off. What will be the direction of the movement of the mud if it comes out at point 'X'?
|
We can write first law of thermodynamics in two forms. $$dU=TdS-pdV$$ and $$dU=dq+dw$$ It is also true that $dw=-pdV$ therefore $TdS=dq$ for every process irrespective of reversibility. What I am missing here?
|
My lecture notes write that the coupling constant for the strong force goes to infinity as the distance goes to infinity.
However the range of the strong force is said to be small.
If the strength of the force (which is represented by the coupling constant) is infinite at large distances, why the short range?
|
Consider an aeroplane of mass M which is flying horizontally ( neglect gravity) with velocity v and dust, which has velocity u in the opposite direction to the plane get stuck to the plane. We need to find the force we need to apply to let the plane move with constant velocity, v.
What I am doing is this -
Take the pl... |
I'm using D. J. Griffiths's textbook Introduction to Quantum Mechanics (3rd ed.) for my introductory university course on the subject. In chapter 5 (starting at section 5.1.1), he discusses the behaviour of identical particles.
For a start, he introduces an elementary spatial wave function for a system of two non-inter... |
My question is originally from an youtube video, which is a tutorial series on digital electronics.
In a nutshell, He (the one in the video) has a predesigned input signal which fluctuates the voltage across the terminals, connected to a resistor. Now, he measures the voltage across it and finds that the voltage rises ... |
So it is well known that standard $D = 3$ Einstein gravity is non-dynamical in the sense that the graviton has no on-shell degrees of freedom (d.o.f $= D(D-3)/2$ and the theory is topological).
However, I have also seen that there are various theories of supergravity with up to $\mathcal{N} = 16$ supersymmetries in $D ... |
I have some questions about the momentum space renormalization group procedure as described in the textbook "Statistical Mechanics of Fields" by Kardar (Ch5). The first is about the rescaling of parameters, and the second is about getting the log of the partition function. I think I understand the basic idea of the ren... |
Suppose we are in a total spin $J=j$ vector space and there is the angular momentum operator $\boldsymbol{J}$. The Hilbert space then has $2j+1$ states:
$$
|m=-j\rangle, |m=-j+1\rangle, \ldots, |m=j-1\rangle, |m=j\rangle
$$
Any state $|\psi\rangle$ can be expressed as
$$
|\psi\rangle = \sum_{m=-j}^j c_{m} |m\rangle
$$
... |
I understand how interference can arise when we start with a coherent light source where all the photons emitted are in phase. As they traverse the double slit, the distances to the screen from each of the double slits is different. The relative phases of the incident waves then sums to give the intensity.
And I have r... |
We know that we can obtain $AdS_{2}$ x $S_{2}$ spacetime as the near-horizon geometry of an extremal/ near extremal RN (or Kerr) Black Hole in asymptotically flat spacetime. It is also known that we can also obtain $AdS_{3}$, from the near horizon limit of the extremal 6d Black string solution.
My question is as follo... |
In the derivation of the Maxwell stress tensor, we see, like here (or in Jackson's Classical Electrodynamics), the charge density $\rho$ upon which $\textbf{E}$ and $\textbf{B}$ are acting being replaced by $\nabla \cdot \textbf{E}$:
$1$. Starting with the Lorentz force law
$$\mathbf{F} = q(\mathbf{E} + \mathbf{v} ... |
Quantum entanglement says that two spatially-separated particles tested for quantum spin on the same orientation will be guaranteed to produce opposite results, but testing in a different orientation invalidates previous measurements performed in different orientations (for either particle).
So the question is, how doe... |
In QFT, elementary particles correspond to irreps of the universal cover of the Poincaré group, and the full quantum field is then the direct sum of fields living in different irreps. So the unitary $U_{\Delta t} $ representing a time translation $ t\mapsto t+\Delta t $ can be written as a direct sum of unitaries actin... |
In Weyl semimetal, there is an analog of ABJ anomaly, which is a $E \cdot B$ term. The ABJ anomaly can be viewed as winding number because of the homotopy group of sphere $\pi_3(S^3)= \mathbb{Z}$ for non-abelian $SU(2)$ gauge group. Usually for abelian $U(1)$ group, we don't have this anomaly because $\pi_i(S^1) = 0$ f... |
Recently I was discussing a problem with one of my students in which she found that two states of the particle in a box were orthogonal and was then asked to give an example of an observable that would make these two states perfectly distinguishable. She thought of the wavelength. This took me by surprise, since I don'... |
in Claudius Ptolemy physic of universe did earth is sphere or Flat ؟
did earth orbit around itself or it is stable?
why he think star have impact on human life ?
|
I have heard this definition of friction: "Friction is the resistance to motion of one object moving relative to another." So is there any friction between the same poles of 2 magnets? I can feel resistance when I move magnets past each other, is there any friction involved between the magnets? Is it possible to have f... |
I have been making a simulation of light traveling in medium from classical physics perspective and while trying to makes sence of a traveling wave packet i realized i don't understand something very fundamental.
Left side of the image:
Nothing to it, we know which way a light ray will refract/reflect from Snell's law ... |
I am reading Introduction to Solid State Physics (by Kittel).
When studying the heat capacity of a metal, conformed by $N$ atoms (each providing one valence electron, which is mobile and capable of electrical conduction), it says that classical statistical mechanics predict that the heat capacity should be $ \frac{3}{... |
Suction force doesn't come under strong nuclear force,weak nuclear force or gravitational force. So does it come under electromagnetic force?
If so then why,like how do charges play a role in the development of high pressure and low pressure?
|
I'm reading a book where I encountered Gaussian curvature, which felt very nature, and it was well defined.
However, in 4 space, people use Riemann curvature tensor, etc.
There's one big distinction was that Gaussian curvature was designed for parametrized surface, where the usual parameter, "time", were all embedded... |
Random matrices may be used in physics to replace Hamiltonian of complex system, for instance in nuclear physics. Eigenvalues of these matrices are simply interpreted as the energy levels (even if we're more interested in the statistical distribution of the levels with this approach) of the nuclei, but what would be a ... |
When studying the properties of solids we always say that electrons are in (stationary) energy eigenstates. The theory of conduction for example (with conduction bands and stuff) follows from the assumption that electrons are in energy eigenstates but why are they in such states in the first place? What prepared the el... |
Take a 2D manifold and thicken it by adding a 3rd dimension of radius $4\pi$.
Now we define fields on this $\psi(x,y,z) = \psi(x,y,z+4\pi)$
Then we say the physics is invariant under the following transformations of these fields:
A translation $$\psi(x,y,z)\rightarrow \psi(x+a,y+b,z)$$
And an 'augmented' rotation:
$$\... |
I have periodic chain of spins $s=\frac{1}{2}$. I want to know what is the most general $SU(2)$ invariant and translation invariant hamiltonian.
My guess is:
$$\sum_i (j_1 S_i \cdot S_{i+1}+j_2 S_i \cdot S_{i+2} + j_3 (S_i \cdot S_{i+1})( S_{i+2} \cdot S_{i+3}) + j_4 (S_i \cdot S_{i+1})( S_{i+2} \cdot S_{i+4}) +j_5 (S... |
In the Wikipedia article on "Geodesics in general relativity" we can find the following statement:
In general relativity, gravity can be regarded as not a force but a
consequence of a curved spacetime geometry where the source of
curvature is the stress–energy tensor (representing matter, for
instance). Thus, fo... |
I'm a scifi writer and have very limited knowledge of astrophysics and I'm working on a story where my character lands on a moving asteroid.
In the original draft of the story, my character is on an escape pod and the asteroid passes by the escape pod. The pod and the asteroid are moving in the same direction and the ... |
The question is simple: why acceleration obtained during the experiment differs from the one obtained from theory, namely, from the $2d$ Newton's law?
Experiment: 1) we use Atwood machine. 2) employ two different loads, one of which is fixed. Then we use Pasco program which records our results when these loads falling.... |
I have written a program for Monte Carlo sampling from Sherrington-Kirkpatrick (SK) Ising model. I have two questions about it:
1- What are some applications of it? I already know training Boltzmann machines and solving optimization problems can be an application, but I was wondering if there are other applications as ... |
A simple and useful expression for the magnetic dipole moment $\mathbf m$ of a closed circuit with constant current $I$, around a curve $\gamma$, is$$\mathbf m \equiv IA\mathbf{\hat n}$$
where $A$ is the area of the surface $S$ with boundary $\gamma\equiv\partial S$, and $\mathbf{\hat n}$ the vector normal to $S$. Obvi... |
Gravitation Page 276 Exercise 11.3 solution indicated that
$$\nabla_\gamma \nabla _\delta e_\beta
=e_{\mu}\Gamma^\mu_{\beta\delta,\gamma} +(e_\nu\Gamma^\nu_{\mu\gamma}) \Gamma^\mu_{\beta\delta}$$
However, using to "Chain rule for gradient" i.e. Eq 10.22
$$\nabla_\gamma \nabla _\delta e_\beta
=\nabla_{\gamma}(e_{\mu}\... |
A bound state is: given a potential vanishing at infinity, negative-energy states must be bound.
How can I distinguish between a bound state and a resonance state in particles physics?
|
I'm very interested in knowing about how much energy would be lost to the atmosphere if you fired a laser or maser into space. I know the laser would probably diverge quite a bit over that distance, and the photons would probably lose a lot of their energy traveling through the medium of air. Just to be specific let's ... |
Setup:
Suppose you have 3 (identical looking) boxes named A,B,C [furthermore they have identical mass]. You are told the following about the boxes:
One of the boxes actually is a uniform mass. We can call that box $B_1$
One of the boxes contains a large wheel inside spinning extremely fast. We can call that box $B_2$ [... |
I know that when air is heated it will have a high temperature that leads to high kinetic energy of particles,high pressure, low density. But, why when hot air rises and expand they get cold ?
Please answer in long sentence.
|
I have a quick question about torque.
If I had a long shaft that was turning a screw and the screw was not turning due to a lack of torque, would making the modification in the picture (without increasing the power of whatever is turning the shaft) increase the torque at the bottom of the shaft?
i.e. would incorporatin... |
Consider a complex scalar particle $\phi$ coupled to an electromagnetic field. The Lagrangian is given by
$$ \mathcal{L} =(D_\mu \phi)^* D^\mu \phi - m^2 \phi^2 - \frac{1}{4} F_{\mu \nu} F^{\mu \nu}$$
where $D_\mu = \partial_\mu - ie A_\mu $ and $F_{\mu \nu} = \partial_\mu A_\nu - \partial_\nu A_\mu$. This Lagrangian ... |
I read an example in my physics book and was not satisfied with that.
Suppose there is a car initially at rest. If the car accelerates then my book says that it is the friction force only which caused this acceleration since it is the only external force acting on the car. But I was not satisfied with that.
What I thin... |
So I know that this is a physics related site, but I'm trying to use a Python library called magpylib to compute magnetic flux at various positions from a joystick magnet. The documentation includes an example of how it can be used.
You'll notice that there's this concept of a "magnetization vector" that describes the ... |
Let's imagine a one dimensional case, where a particle is moving with a velocity $v$ and an acceleration $a$. Thus
$$a=\frac{\mathrm dv}{\mathrm dt}\tag{1}$$
Applying the chain rule, equation $(1)$ can be rewritten as
$$a=\frac{\mathrm dv}{\mathrm dx}\frac{\mathrm dx}{\mathrm dt}\Longrightarrow \boxed{a=v\frac{\mathrm ... |
We have been taught that the force on a moving charge due to magnetic field is:
$$\vec{F} = q(\vec{v} \times \vec{B})$$
When I asked my professor about its source, he said that it was derived from mere observations. But from my knowledge, generally formulas derived from observations contain some proportionality constan... |
I'm taking an MIT OpenCourseWare talking about the squeezed state:
https://www.youtube.com/watch?v=NXgobnaBN7U&list=PLUl4u3cNGP60QlYNsy52fctVBOlk-4lYx&index=15
At 1:14:12 Prof. Zwiebach claimed $\frac{1}{\sqrt{cosh\gamma}}e^{-\frac{1}{2}tanh\gamma\hat{a}^{\dagger}\hat{a}^{\dagger}}|0\rangle = e^{-\frac{\gamma}{2}(\hat... |
Suppose an inductor is connected to a source and then the source is disconnected. The inductor will have energy stored in the form of magnetic field. But there is no way/path to ground to discharge this energy? What will happen to the stored energy, current and voltage of the inductor in this case?
|
I get confused understanding Constant or uniform Velocity and acceleration when I understand constant speed which means that same distance traveled at same time.
So constant or uniform velocity means same distance and same time which so no change in velocity or no change in speed. Hence if a say 4 m/s constant or unif... |
In classical electrodynamics there is a current and potential four-vector. The covariant force density in a charge continuum according to wikipedia is
$f_\alpha=F_{\alpha\beta}J^\beta$
But I'm not sure how to generalize it to classical chromodynamics since there are eight current and potential four-vectors. Would ther... |
In the (currently unanswered) Math SE question Can there be an energetically unbounded three-body orbit where escape is impossible due to conservation of angular momentum? I've I'd written†:
The total energy would be the sum of the kinetic and potential energies
$$E = \sum_{i=1}^{3}\frac{1}{2}m_i v_i^2 - \sum_{i=1}^{3... |
I have been studying Young Tableaux representation from youtube to represent $2\times 2$ and other examples to in $SU(n)$ symmetry. But i am unable to understand nor able to find relevant answers of how to represent conjugate i.e how can one write $\bar{3}$ in a square box in $SU(3)$ representation is actually 2 and $\... |
Work done by action-reaction pair of tension force on a system is zero if the string is inextensible
I am trying to understand this statement taking the following arrangement in consideration. Here, a block of mass m initially at rest, is released such that it extends the spring as it moves downwards. The spring is ... |
An infinite length conductor (1) with electric current I creates a magnetic field $B=\frac{μ_0I}{2πr}$, where r is the distance from the conductor. Two parallel long wires, (2) and (3) (in the direction of EH and ZΘ as shown below) are perpendicular to conductor (1) and in the same plane. On top of them, the rods EZ an... |
I am looking for the Pauli vector in spherical coordinate basis, like so:
$$\vec{\sigma} = \sigma_r \vec e_r + \sigma_{\theta} \vec e_{\theta} + \sigma_{\phi} \vec e_{\phi}$$
instead of
$$\vec{\sigma} = \sigma_x \vec{x} + \sigma_{y} \vec{y} + \sigma_{z} \vec{z}$$
in cartesian coordinates
At the end of a day I want cal... |
In many textbooks, the discussion of conserved quantities in General Relativity has the following conclusions:
If we assuming a spherically symmetric spacetime in the form
\begin{equation} \mathrm{d}s^2 = -\mathrm{e}^{2 \phi}\mathrm{d}t^2
-\mathrm{e}^{2 \lambda}\mathrm{d}r^2 +r^2 \mathrm{d}\Omega^2 \quad , \end{equa... |
I want to ask about the interpretation of electric potential as it relates to this simple problem : " "A $0.800$ mm diameter ball bearing has $1.50 \times 10^9$ excess electrons. What is the ball bearing's potential?"
The electric potential is the amount of work needed to move a unit of charge from one point to another... |
From my understanding, binding energy is the energy required to separate all nucleons in a nucleus an infinite distance away from each other. I cannot tell whether this ignored the effect of one of the mentioned forces, or a combination.
After fission of a large nucleus, we know the decay products are more stable. Howe... |
The object distance ($u$), image distance ($v$) and the focal length of a spherical mirror ($f$) are related by the well-known formula (using the appropriate sign convention):
$$ \frac{1}{u} + \frac{1}{v} = \frac{1}{f} $$
The location of the image happens to coincide exactly with the image of the point object $O$ when... |
One can use the Kretschmann Scalar to investigate curvature singularities, and in the case of Schwarzschild metric expressed using Kruskal–Szekeres coordinates or any other coordinates it is clear that the only singularity is at $r=0$, but I was wondering is there a "smart" way to calculate it, it seems to me that it w... |
I'm in high school and wanted to get a few things cleared up.
Isothermal process is defined as a thermodynamic process where temperature remains constant.
Does this mean that temperature remains constant at every instant? Does an isothermal process have to be reversible?
The Joule expansion of an ideal gas is an irre... |
When computing a generating functional, $Z[J]$, in terms of the generating functional of Green functions, $Z[0]$, in my lecturer's notes we reach the following terms:
$$Z[J]= \mathcal{N} \int Dq \hspace{1mm}\text{exp} \left( \frac{-i}{\hbar} \int dt V(q(t))\right)\text{exp}\left(\frac{i}{\hbar} \int ds \hspace{1mm} L_0... |
If you look at this plot of proton Bragg peak at different energies.
You can see that the Bragg peak shifts right (which makes sense) but also the height and I think the width of the brag peak is also reduced and widened, Physically, why does this happen? I suspect it has something to do with the 1/v^2 stopping power ... |
This article states that the average human has a mass energy equivalence of 7.8 septillion joules of energy
Converting this into a temperature using $E=k_B T$, we have a temperature on the order of $10^{41} K$, which is obviously not the case.
I’m obviously being dumb, but what am I missing?
This is an awful lot of en... |
Newton wrote the bulk modulus for speed of sound by writing the ideal gas law in differential form, and, laplace wrote another expression by taking writing the differential form of the adiabatic gas law.
Now what's weird for me, here, is that there are two expressions for bulk modulus?? so, which is the correct one? I ... |
Are the terms shear viscosity and viscosity for fluids interchangeable, or do they mean different things?
|
I would like to know how to use a battery to charge a piece of plastic like a feather duster.
I know static electricity is supposed to come with friction for example. But is there a way to do it with a battery to maintain a charge level in the air?
|
I'm learning about complex refractive index, and I know it has something to do with absorption, so a light wave which is propagating in $z$ gets absorbed by the following law: $$e^{- \frac{2 \pi}{\lambda_0} n_{\mathrm{Im}} z},$$ where $n_{\mathrm{Im}}$ is the imaginary part of the refractive index and $\lambda_0$ is th... |
I have a confusion regarding the semiconductors.
Is the type of doping the only factor to decide what type of semiconductor we will get? For example:
doping of Si with phosphorus $\Longrightarrow$ n-type semiconductor
doping of Si with aluminum $\Longrightarrow$ p-type semiconductor
Can a semiconductor be n-type (... |
When the rate of acceleration changes its sign how does the velocity change? When another derivative of distance with respect to time is increased how does it affect factors like displacement and velocity?
|
I often hear Bremsstrahlung being discussed in relation to electrons, for example, x-ray generation. Although I was reading a review on Proton Therapy and when discussing the influence of the various interactions within the body it quotes
proton Bremsstrahlung is theoretically possible, but at therapeutic
proton beam ... |
I have been reading the Srednicki's QFT textbook (available online at https://web.physics.ucsb.edu/~mark/qft.html) and in Chapter 34 the left and right-handed spinors are discussed. There is a step in the logic that I simply cannot follow.
The discussion starts with a left-handed spinor field transforming according to:... |
Why is the normal force applied from the corner? How can I find the application point of the normal force?
|
Which is more valid for The pressure intensity at a point in a fluid is the same in all directions, only when:
The fluid has zero viscosity and is at rest? or
There is no motion of one fluid layer relative to an adjacent layer?
Please provide an explanation.
|
In the expression of time derivative of expectation value of position, it is mentioned in book (Introduction to Quantum Mechanics by DJ Griffith) that inside the integral, the differentiation with respect to position $x$ will be zero, so the time derivative only applies on probability density.
But I don't get the point... |
Can we mathematically show that water flows from high-pressure region to low-temperature region and why particles flow from a region of higher chemical potential to lower on the basis of the principle of increase of entropy?
|
When will the normal stress be the same in all directions at a point in a fluid? Is it when the fluid has zero viscosity and is at rest or one fluid layer has no motion relative to an adjacent layer? Please give an explanation.
|
Consider the well:
$$V(x) = \begin{cases}
\infty&\text{if }x<0 \\
0&\text{if }x\in\left(0,L\right) \\
\infty&\text{if }x>L.
\end{cases}$$
Solving the time independent Schrödinger equation on the well $$-\frac{\hbar^2}{2m} \frac{∂^2\psi}{∂x^2} =E\psi,$$ will yield one of the solutions $\psi = 0$.
Some books say t... |
I am looking for some thorough notes on the Collins-Soper frame. This is a reference frame used in Drell-Yan process in hadron colliders.
|
I'm reviewing material for my quantum information module and I came across the following question:
"A projective measurement in the standard computational basis is to be performed on the
first qubit of a two-qubit system in the state
$$|\Psi\rangle = c_{00}|00\rangle + c_{01}|01\rangle + c_{10}|10\rangle + c_{11}|11\ra... |
I was studying nuclear physics this day and I read about radioactive decays.
$\beta$-plus decay turns one proton in the nucleus into one neutron, one positron and one neutrino.
I was wondering about the electron count in the process of $\beta$-plus decay and also in any other decays. Let's suppose if we have a $\beta$-... |
My question is:
n-qubit product state.
$$|\psi\rangle=(a_1|0\rangle+a_2|1\rangle)\otimes(b_1|0\rangle+b_2|1\rangle)\otimes \cdots$$
n-qubit Entangled state
$$|\psi\rangle=(a_1|000\cdots000\rangle)+(a_2|000\cdots001\rangle)+(a_3|000\cdots010\rangle) \cdots$$
In the entangled states there are $2^n$ different amplitudes ... |
The two-dimensional Ising model with the nearest-neighbour interactions enjoys a $\mathbb{Z}_2$ symmetry under $S_i\to -S_i$; it displays sponatebous symmetry breaking at a finite temperature $T_C=2J[k_B\ln(1+\sqrt{2})]^{-1}$ and nonzero spontaneous magnetization is developed below $T_C$.
Now, the definition of magneti... |
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