instruction stringlengths 31 24.3k |
|---|
The motion of a ball rolling from rest down a plank is measured by marking its position each second. From $t=3s$ to $t=4s$, the ball travels $0.56m$. Calculate the magnitude of the acceleration of the ball.
I calculated the average velocity of the ball between $t=3s$ to $t=4s$ like so:
$Δv=\frac{Δs}{Δt}$ = $\frac{0.56}... |
I curious to know if there is a way to do simulation of quantum ising model with transverse field.
The method I know is - do classical ising model simulation in d+1 dimension which essentially maps to d dimensional ising model by Suzuki-Totter formalism.
But I was wondering if simulation of ground state of ising model ... |
I'm working through the proof of Wigner's theorem in Weinberg's The Quantum Theory of Fields Volume 1 Chapter 2 Appendix A pp. 91. Consider the following steps of the proof
Let $\left\{\psi_{k} \epsilon \mathbb{R}_{k}\right\}_{k=1}^{n}$ be a complete orthonormal basis. Then,
$$
\left|\left\langle\psi_{k} \mid \psi_{l}\... |
It is well known that the symmetry operations $U$acting on the operators could be written as
$$U AU^{-1}$$
Now I want to know the logical origin or motivation of this form of operation, my thought came from my QM class that the symmetry operators acting on states like $U |\Psi \rangle$, so acting on operators is just l... |
We know that adiabatic law for an ideal gas is,
$$ PV^{\gamma} =C$$
the differential of this under constant pressure is,
$$ P \gamma V^{\gamma-1} dV = 0$$
Now, the pressure and volume can't be at all points in process zero, so it must be $dV$ that must be zero. So does that suggest such a process is not feasible at al... |
Suppose an object is moving with varying acceleration in time.
What does it mean when it hits a point where $\frac{dv}{dx}=0$?
Does it mean the object has hit maximum velocity?
Assume the object starts from rest and then ends its journey at a rest position.
|
I've been told that the set of no-signaling correlations is a polytope.
How do I find the extreme points of 2-2-2 no-signaling correlations? Here "2-2-2" refers to the two-parties scenarios in which each party has two inputs to choose from, and can observe one of two possible outcomes.
|
I am trying to find an expression for the overlap between the eigenstates of different spin component operators in a spin-S system. Say I have operators $\hat{S}_i,~i=x,y,z$ with eigenvalue equations $\hat{S}_i|S,m_i\rangle=m_i|S,m_i\rangle$. I now want to find an expression for $\langle S,m_i|S,m_j\rangle,~i\neq j$.
M... |
I have a general question about the relativistic momentum equation. The same question could be asked about the relativistic kinetic energy.
What reference frame is used to measure the velocity, $v=\frac{distance}{time}$?
$$\mathbf{p}=\frac{mv}{\root{2}\of{1-\frac{v^{2}}{c^{2}}}}$$
Suppose the momentum of an electron is... |
Knowing the wavefunction $\Psi(x,y,z,0)$ is enough to know the functions for $\frac{\partial^2\Psi(x,y,z,0)}{\partial{x^2}}$, $\frac{\partial^2\Psi(x,y,z,0)}{\partial{y^2}}$, $\frac{\partial^2\Psi(x,y,z,0)}{\partial{z^2}}$, seeing as how they are second derivatives of the wavefunction with respect to spatial coordinate... |
Richard Feynman made the following statement:
the relationship between the gravity forces and electrical forces
remains unknown
in the interview linked here.
In context, he made this statement partly as to contrast the well-known relationship between magnetism & electricity.
As I have read, the energy in the electrom... |
I have a homework question about gyroscope rotation, but I will describe my confusion more specifically as follows:
Below is the setup of the problem. I understand the concept that if the rotor is made to spin, then there is an angular momentum generated in the direction given by right-hand rule, in this case to the ri... |
Due to the laws of gravity and electromagnetic attraction (decreases with $\frac{1}{r^2}$) we know that space should be limited to 3 dimensions.
At the same time we know that gravity bends space. All visualization of that are basically elastic 2D membranes where heavy balls are placed to create "gravity wells" of vario... |
I'm assuming questions about the third law being invalid in relativity have already been asked on this site, but I'm specifically asking about how momentum is still conserved inspite of it.
Consider only two particles in the universe. In some reference frame, they're moving with velocities $v_1(t)$ and $v_2(t)$ at time... |
If you are given a Lagrangian in coordinates which are not cyclic, is there a rule for finding a transformation of the coordinates to another set of coordinates where one of them is cyclic?
|
I have a use case where I want to produce fog (an aerosol) using an industrial grade high-volume fog generator and then I would like to direct the resulting fog to different locations i.e. small boxes in the same room. This way, I can have concentrated fog where I need and keep rest of the room space clear.
Being a phy... |
In the Stern-Gerlach experiment silver atoms with random magnetic moment direction are fired through a magnetic field $\vec{B}$ parallel to $\hat{z}$ with a nonzero gradient $(\nabla \vec{B})$ also parallel to $\hat{z}$. The classical interpretation was that the trajectory of the silver atoms will curve proportionally... |
One of the basic expression that goes without much thinking is the potential energy expression of a magnetic dipole in a magnetic field, $$ U = -\mu\cdot B $$
In the case of electric and gravitational field, sources of potential energy, in general, can be realized by the conservative nature of the fields, meaning that ... |
I am writing an equation using the Hubble constant. My work is based on Dodelson's article on sterile neutrinos which uses a C$+$HDM model.In it a value of $h=0.5$.
But when reading the more recent Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Observations: Implications for Cosmology, which uses a $\Lambda$CDM... |
**
So as we can see the pulley attached to the body here is a movable pulley.In Illustration (A) if the block attached to the pulley is moved in the direction of the arrow with an displacement of X meters then we can state that the pulley attached to the object via string will also move with the block by a displacement... |
In Everett's Many-worlds Interpretation of QM, Schrodinger's equation is never violated (unlike in Copenhagen Interpretation). But how is this even possible? When you measure a system with respect to an observable $M$, the state of the system will turn into an eigenstate of $M$, which, may not necessarily be an eigenst... |
The higher the density of an object is the more it will cause distortion on space and time.
I want to know the equation that links density to time dilation.
I found the Lorentz equations that link speed with time dilation but I cannot find the equations that does it for gravity...
Any help?
|
I have read many questions on this site about how do transitions occur ? What happens during transition ? The answers are extremely good.
What I couldn't understand is why is frequency related to the energy released during the transition? What causes this frequency (since I don't think electrons are oscillating while t... |
Suppose a child stands on a merry-go-round and rotates with it at the same speed, with coordinates centered at the center of the merry-go-round.
The center of a merry-go-round is a pole going into the ground.
Take our closed system to be the child and merry-go-round (which includes the pole). Notice this system has out... |
We all know that when we calculate the divergence of point charge at origin, it turns out that it's zero at all points except origin and infinite at origin, which is called Dirac delta function. refer here
$$ \nabla \cdot \mathbf E = 4\pi\delta^3(r).$$
Now let's consider a continuous charge distribution in space. We ar... |
I bought a Xiaomi sensor that measures light intensity. The data I get from it is called
illuminance_lux and the unit is supposed to be lux
illuminance, no unit is provided
"Illuminance" is defined in Wikipedia as
In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a mea... |
Mars has a $g$ of about 38% of Earth's, but an escape velocity that is 45% of ours.
Not a large difference, but there must be a reason.
|
What does the statement a body is accelerating 10 km / hr per second means? I have always heard a body accelerating 10 km/sec square?
|
This is a question I’ve been thinking about for a while. If I’m standing in the middle of a straight road, during night, I can see a car coming towards me because of its lights even if it is kilometers away. Notwithstanding, the driver can not see me because the car will brighten the road only few hundred meters furthe... |
In the case of 1D Hamiltonians not explicitely dependent on time, our professor claims that the "period" of the separatrix is necessarily infinite and must pass through an unsable equilibrium or connect two such points. Although I can kind of see the hand-wavy argument, I don't understand how to prove it.
I think we ar... |
I have seen that it is often stated that Babinet's principle is only valid in the far field limit/Fraunhofer condition as it makes use of the linearity of the fourier transform.
However couldn't you use the linearity of any integral (even the Kirchoff-Fresnel integral) to still use Babinet's principle? I don't see how ... |
I was wondering what is the centripetal force of a body rotating in a circular motion. I know that the centripetal force of a point mass is $mv^2/r$. I only have done an introductory physics class so I can not find the answer.
|
Consider a system of $N$ molecules, and they can each possess either property A or property B. No molecule can have no property, or both properties at the same time. Let $x$ be the fraction of having property A, and $-n\epsilon$ is the penalty the system incurs in energy when $n$ molecules exhibit property A, and the s... |
Birrell and Davies in their book state that if $\langle \psi|T_{\mu\nu}|\psi\rangle = 0$ in one reference frame then it must be zero for all others whereas the particle content may vary for different observers (Section 3.3, pg 49).
In the 1976 paper by Davies and Fulling, it was shown that for uniformly accelerated mov... |
Question
So I read this interesting link:
The most glaring problem is that the state spaces of classical and
quantum mechanics are completely different, so you can’t have a simple
limiting procedure unless you describe how you’re going to map one
onto the other
and was wondering if there was any book which was dedica... |
So the problem is a point charge is located at the origin of the coordinate system and a cube of side length 2a is centered at the origin and I am trying to find the electric field, and flux due to the point charge.
So far, I have said that the electric field, $E = \frac{q(r_2-r_1)}{4πe_o|r_2-r_1|^3}$ and attempted to ... |
Especially new electric cars often come with aerodynamic wheels that look like a turbine with twisted blades. What is the point of this? I mean, e.g. in cycling they use just a simple disc wheel when aerodynamic efficiency matters during individual time trial. Why is this "turbine" better than a disc? Or is it?
|
All equation's I've seen for Millikan's oil drop experiment involve quantitatively knowing the Voltage beforehand. I don't see a way to calculate the Voltage using Coulomb's law without knowing the correct unit for coulombs, and I don't see how this could be done either using Ohm's Law, seeing as the unit Ampère requir... |
I have a sphere where the upper half surface has a potential of $V_0$ and the lower half is grounded and I have to find the potential everywhere (using the Laplace solution for spherical coordinates). But when I try to equate $\Phi(R,0)=V_0$ (for $r=R$ on the surface and $\theta=0$ for the top of the sphere) and $\Phi(... |
According to wiki, the wave function for a free particle is:
$$ \psi(\mathbf{r}, t) = Ae^{i(\mathbf{k}\cdot\mathbf{r}-\omega t)} $$
that with the necessary restrictions and uni-dimensional became:
$$ \psi(\mathbf{r}, t) = Ae^{i k \left( x-\frac{h}{2m\lambda} t \right) } $$
this wave function must fulfill normalization... |
Forgive me if my reasoning is based on flawed logic and information. I am no physics expert.
As I understand it when light strikes an object the energy of the photons is absorbed by the atoms that make up the object. An atom's electrons can only orbit its nucleus at one level or another, nothing in between. When the at... |
I have no problem with the solution provided but, I have a problem with understanding it's meaning.
Shouldn't the two solutions for b) add up to be the period? If not, why?
|
I am trying to understand Luttinger's research paper
Theory of Thermal Transport Coefficients, J. M. Luttinger Phys. Rev.
135, A1505 – Published 14 September 1964
While I am able to understand the main concept of his work, I am unable to reproduce his mathematical steps.
I wonder if there is any book or lecture notes... |
As we all know, if an optical fiber is designed with the right material and properly bent, light can be transmitted along the fiber with very little attenuation.
Figure 1 shows the interaction of radiation F with a conical structure. The cone is a hollow mass with an internal reflector layer or a homogeneous mass of tr... |
This question stems from the confusion that I feel after reading this popular blog post by Sabine Hossenfelder. It is based on this paper which is paywalled, unfortunately.
The claim is the following:
Rather, as presented in his 1969 Tellus paper, Lorenz intended the phrase to describe the existence of an absolute fin... |
Does anyone knows the formal definition of Coupling efficiency?
I have been reading the term in photonics devices and optics.
I have been searching for it, but I could not find any.
Thanks for the help.
|
Considering that all our metrics is now based on physical constants as measured here on earth,
With earth having both gravity and velocity, as well as the whole solar system having too, and special relativity telling us that our perception of time changes based on those factors,
Will our metrics and constants have to b... |
In Zee's Quantum Field Theory in a nutshell, he discusses the quantity $W(J)$, where
$$\left<0\middle| e^{-iHT} \middle|0\right> = e^{-iET} = Ce^{iW(J)}$$
and for a free theory with a source $J = J_1 + J_2$ where $J_1$ and $J_2$ are localized in space, we have
$$W(J) = -\frac{1}{2}\int \frac{d^4k}{(2\pi)^4}J_2^*(k) \fr... |
In an Atwood machine where we assume the string is massless, I understand that the tension in the string is constant throughout. However, I'm having a little trouble imagining the forces on the pulley itself. I'm not sure why the pulley feels $2T$ force downwards, where $T$ is the tension in the string.
|
There is an ideal membrane, defined by axes $x \in (-\infty,+\infty)$ and $y \in (0,+\infty)$. The membrane has an homogeneous surface density $\sigma = \frac{dm}{dS}$ and it is streched in every direction by a fixed power: $T=\frac{\Delta F}{\Delta L}$. The side of the membrane that's parallel to axis $x$ is fixed at ... |
In David Tong's lecture notes on quantum field theory, at the top of page 38, we calculate the amplitude for a particle to propagate from $y$ to $x$:
$$\begin{align}\langle0|\phi(x)\phi(y)|0\rangle&=\int\frac{\text d^3p\text d^3p'}{(2\pi)^6}\frac{1}{\sqrt{4E_\vec pE_{\vec p'}}}\langle0|a_{\vec p}a^\dagger_{\vec p'}|0\r... |
I've read, that because they are readily ionized and strongly interacting with the laser light, they could be used to study interconversion mechanisms between photon, chemical, thermal etc. energy. Why the ionisation is a factor here, how does it help to study quantum systems?
|
Even in the simplest case of a free particle, so subjected to the Hamiltonian:
$$H=\frac{\hat{p}^2}{2m}$$
we often need to find the explicit form of the eigenvalue equation:
$$H|E\rangle=E|E\rangle \ \ \ \ \ (1)$$
this explicit form is:
$$-\frac{\hbar^2}{2m}\frac{\partial ^2 \psi _E(x)}{\partial x^2}=E\psi _E(x) \ \ \ ... |
I was watching a program on the future of the Universe and it got into the eventual heat death resulting from Hawking Radiation as the last hurdle till nothingness (assuming the unproven theory of proton decay is real).
One of the scientists in the show (Michio Kaku) presented a Darwinistic model, an idea by Lee Smolin... |
In his famous paper, More is Different (link), Philip W. Anderson states that in the context of quantum mechanics :
[...] the state of the system, if it is to be stationary, must always have the same symmetry as the laws of motion which govern it.
However, that does not seem to be true in general. The most trivial ex... |
I was exploring cases of Gauss's Law application on different surfaces in the Professor Moyses Nussenzveig book (Basic Physics Course, Vol.III) and I'm having a hard time understanding completely a specific example. Basically, there is a coaxial cable formed by a cylindrical shell of length $L$, inner radius $r1$ and o... |
In his book Quantum Space page 82, Baggott says "In fact, elaborate QCD calculations demonstrate that about 95 percent of the mass of a proton or neutron is derived from the energy of massless gluons that carry the colour force between the quarks.... We see that Einstein's great insight was indeed that $m=E/c^{2}$ the... |
I saw a proof that shows that there is no such a thing as magnetism. I think the fault in the proof is with simply connected regions. Proof is as follows:
One of Maxwell’s equations tell us that
$$\nabla\cdot \mathbf{B}=0$$
where $\mathbf B$ is a magnetic field. Then using the divergence theorem, we find
$$\iint_S\math... |
"Does the Sun have enough gravitation to bind its hydrogen/helium plasma?"
So my question arises from the fact that high energy (or high temperature in other words) hydrogen or helium gas just explodes, instead of being bounded in one place. Then I guess the Sun has enough gravitation to bound the ionized particles. I ... |
I have a derivation of
$$\left.\frac{\partial H}{\partial P }\right|_T = V - T\left.\frac{\partial V}{\partial T}\right|_P$$
that makes use of $S$ and $G$.
Here it is succinctly
$$dG = VdP - SdT$$
$$\left.\frac{\partial V}{\partial T }\right|_P = -\left.\frac{\partial S}{\partial P}\right|_T$$
$$dS = \left. \frac{\pa... |
In the solution for Peskin & Shroeder 2.2 where the Hamiltonian density obtained from the Klein-Gordon Lagrangian is given by:
$$
H = \pi^* \pi + \nabla \phi \cdot \nabla \phi^* + m^2 \phi^* \phi \\
= \pi^* \pi + \phi ^ * (- \nabla ^ 2 + m^2 ) \phi
$$
Im confused with how the last equality was obtained. The notes sa... |
Every black hole has a singularity. But the singularity is covered by a thing called 'Event horizon'or ' Schwarzchild Radius'. Our universe is originated from a naked singularity. By naked singularity, I mean that the singularity wasn't covered by the event horizon. Is it possible that a black hole has a universe in it... |
I was following the proof of Wigner's theorem from Weinberg’s book Quantum Theory of Fields, volume 1, pp.91-94 and got stuck in the middle: the proof proceeds as follows for arbitrary state vector:
Now consider an arbitrary state-vector $\Psi$ belonging to an arbitrary ray $\mathscr{R},$ and expand it in the $\Psi_{k}... |
Black-body radiation, as I understand it, is radiation in thermal equilibrium at a fixed temperature with a cavity. The spectrum of such radiation follows the famous black-body distribution curve. But quite surprisingly to me, the radiation coming from the surface of the Sun also follows the black-body curve despite th... |
Below is the image depicting my confusion. In the top diagram, there is a horizontal rod with X marking the axis of rotation. Since the rod is horizontal, intuitively the rod will not rotate. This is indeed true since when I take the torque at the center of mass I get 0, as no other force is acting on the rod except gr... |
As the title suggests, after going through a lot of Wikipedia, and references of books, I have learned that: The little group of a massive spin-1 particle is $SO(3)$, while the little group of a massless spin-1 particle is $ISO(2)$ or $E(2)$, as far as the unitary representation of Poincare group is concerned.
My quest... |
Consider a non-conducting ring with positive charge fixed on uniformly . This arrangement is rotated about the axis of the ring with an uniform angular velocity.
I understand that this arrangement will produce both an electric field and an magnetic field. I have further found out somewhere that the electric field wil... |
In the diagram given below is a mass $m_1$ placed on an inclined block of mass $m_2$. And the question is to find the distance moved by the wedge when m1 reached the lowest point. The solution was given that as there is no external force on the system the center of mass doesn't move. My question is why isn't there an e... |
The paper in question is Ref. 1. This is a traversable Einstein-Rosen bridge. However, this paper calculates that an in-falling observer will cross the throat of the wormhole in finite proper time but infinite frame time. Now, I am a bit concerned with the infinite frame time part. Does that mean that people who cross ... |
I attempt to understand one of the examples of the application of Noether theorem given in Peskin & Schroeder's An Introduction to Quantum Field Theory (Page no. 18, Student Economy Edition). The relevant portion of the text is given below.
If I understand the derivation and the corresponding discussion here properly,... |
I know experience-based questions are a bit tricky on this site but isn't every theory based on common experience?
Every time I hear an air jetliner flying over at a high altitude it seems the engines are sort of humming. The sound isn't steady in time but instead little variations are to hear. They are not making the... |
In my CIE A level course, the gravitational potential energy of a mass in a gravitational field is defined as the work done in bringing the mass from infinity to that point without changing it’s k.e. energy.
I thought about the gravitational potential energy if a system of more than 2 masses; it would obviously be lowe... |
Electrons have a mass, as a particle with mass, they experience most effects of objects with a mass. So do they experience any sort of wind resistance? Or is that simply explained by their cross section interaction probability with a given particle?
|
I used to think of them as separate independent rules. But after making the Why do we have to revise the definitions of momentum and force in special relativity? post, I realised that they're not separate.
How are they connected though? Does one imply the other? Why would some velocity transformation other than the Gal... |
The ideal hexagonal close-packed structure was said to have a fixed $c/a$ ratio. However, in terms of three-dimensional Bravais lattices, it looked like Primitive (P) Hexagonal, and there didn't seem to be a reason for which $c$ could not be stretched much longer.
What exactly is an ideal hexagonal close-packed structu... |
As the Sun's coronal belt is made up of protons and electrons constantly scattered by photosphere's sunlight and as these particles are forced to do loops due to Sun's magnetic field is it possible that they are more stable at the equator because the magnetic field orientation doesn't permit them to go further into spa... |
Consider a (fermionic) second-quantized lattice model. We know that we can make $c^*(r')c(r)$ gauge-invariant by applying Peierl substitution, i.e.,
$$
c^*(r') \exp(iA_{r'r})c(r)
$$
so that if $c^*(r)\mapsto c^*(r) \exp(-i\chi(r))$, then the above formula maps to that with vector potential $A_{r'r}\mapsto A_{r'r} -(\ch... |
I have to write a research paper (don't know the exact english translation) for school. The question I want the paper to answer/discuss is: 'Can the universe be predicted at sub-atomic level?'
The desired structure of my paper is as follows:
Introduction
An example of an accurate prediction, either through the use of ... |
Suppose that a tower is releasing radio waves. These waves are received by an antenna. The radio waves apply force to the electrons in the antenna. My question is that by newton's third law, every action must have an equal and opposite reaction. But in the above case of the antenna, I am able to identify only the actio... |
I know that electric field strength is force per unit charge but what I have not yet understood properly is that how electric field can obey the laws of vector addition and subtraction excluding the linear situation?
Does electric field completely obey the triangle law of vectors? Does it produce a resultant like other... |
How big must an asteroid be before gravity makes it round and hydrostatic equilibrium comes into the equation? Let's say that being a round planet requires a radius error of $\frac{\delta R}{R}$ that is less than 0.01. In terms of bulk modulus ($K$), density ($\rho$), and $\frac{\delta R}{R}
(r)$, how would I be able... |
We know that empty space is not really empty, but
there are virtual particle pairs of electrons and positrons that are constantly generated and annihilated.
We also know that in an atom, there is empty space for the most part. Have we ever wondered how these virtual particles affect the moving of an electron? What if t... |
If someone could just show me how to solve part A, I think I can try the rest on my own. Here is the question:
A model rocket is launched straight upward with an initial speed of 47.0 m/s. It accelerates with a constant upward acceleration of 2.50 m/s^2 until its engines stop at an altitude of 100 m.
a) What is the max... |
When we add two vectors(A and B), we get one resultant sum vector(C).
i.e. adding two different directions gives us one resultant direction.
So in the same way if a hypothetical car was trying to go in two different directions at the same time somehow , can the direction it will end up going be figured out by simply a... |
I tried to search for papers for similar experiments but I couldn't find any. Could someone please help me find resources for my experiment. It would also be great if someone could give some suggestions for my research. Like the methodology I should use, fixed variables, and so on.
|
Consider a current-carrying wire.
In the first case, the current in the wire is increasing with time. Since the magnetic field is changing, EM waves will be produced. My question is what will be the value of the magnetic component of EM wave. Since the magnetic field due to the wire never becomes zero, will the magnet... |
Problem: Show that if a projectile is shot from a height $h$ with speed $v_0$ the maximum range obtains for launch angle $\theta = \arctan(\frac{v_{0}} {\sqrt{2gh+v_{0}^{2}}})$.
I'm able to derive the general equation for range (i.e. $y \neq0$) without any bother, but I get all tangled up in the differentiation and t... |
In Condensed Matter Field Theory (2nd edition) by Altland/Simons there considered antiferromagnetic chain with Hamiltonian:
$$H = J\sum_{<n,m>} S_nS_m = J\sum_{<n,m>}[S^{z}_n S^{z}_m + \frac{1}{2}(S^{+}_{n}S^{-}_{m}+S^{-}_{n}S^{+}_{m})]$$
When apply a canonical transformation to the Hamiltonian
in which the spins on on... |
ABCD is a track with a horizontal section BC of length 5 m. A 0.3 kg steel sphere is released from a point on the slope AB and it rolls towards the end D of the track. A stop watch was started shortly after the sphere passes B. The times at which the sphere passes various marks on the horizontal section are as follows... |
It is commonly stated that increasing voltage of the source reduces power loss. If voltage of source is increased current through the circuit increases, resulting in more power loss (than with less voltage) across the component and also through the wire.
$P=I^2R$
To reduce power loss across wire, we need less current t... |
I am not a student nor a scientist. If a photon is a wave until it is measured somehow, how can it have a spin? A wave is a wave. Is spin simply a mathematical tag that we give to particles? Or do particle waves not have spin until they collapse back into an actual particle?
|
When an object is at rest the force of gravity and normal force cancel out. However, when place on an inclined plane the downward force of gravity is not equal to the normal force that is perpendicular to the ramp. Why is that?
My second question is why is normal force perpendicular to the ramp?
|
Assume that there is no friction occurring.
In case (A)-:
*If the pulley is moved by X units in forward direction(which is shown through dotted lines) then clearly we can say that string L1 and L2 will also moves X units to keep them attached to it.Now,if the pulley moves in forward direction as shown then we can anal... |
To the best of my knowledge, the CMB power spectrum is obtained from a statistical analysis of the observed temperature anisotropies of the CMB sky. Is there a way of getting the power spectrum theoretically from the quantum aspects of a given model of inflation? In that case, one can compare that with the experimental... |
The question is as follows,
Consider a simple harmonic oscillator in its ground state. An instantaneous force imparts momentum $p_0$ to the system. What is the probability that the system will stay in its ground state.
My approach to the problem is as follows,
Since the Hamiltonian and the momentum operators don't comm... |
I am looking for step-by-step, clear, detailed and rigorous explanations of methodologies to calculate electronic bands of semiconductor, GaAs as an example, by solving the Schrödinger equation with the k.p method. Everything I could find so far assumes some degree of prerequisite knowledge. Any advice on readings?
|
I see a lot of images, including one in my textbook, like this one, where at the ends of a uniform field, field lines curve.
However, I know that field lines are perpendicular to the surface. The only case I see them curving is when drawing field lines to connect two points which aren't collinear (like with charged sp... |
I'm quite confused, If it's a state function it is dependent on the properties of state, after we loop a cycle, we return to the same point and hence evaluating entropy at that state and subtracting with original entropy at start, it should total to zero. However the Clausius inequality states that it's less than or eq... |
First, consider two uncoupled harmonic oscillators $x_1(t)$ and $x_2(t)$ with classical Lagrangian
$$
L_0 = \frac{1}{2} m_1 \dot{x}_1^2 - \frac{1}{2} m_1 \omega_1^2 x_1^2 + \frac{1}{2} m_2 \dot{x}_2^2 - \frac{1}{2} m_2 \omega_2^2 x_2^2
$$
where $m_j$ and $\omega_j$ are respectively the masses and frequencies for each... |
Assume that Earth has an atmosphere made out of a very efficient greenhouse gas (e.g. a very, very thick wator vapor atmosphere).
In that case, what would be the surface temperature (or the temperature of the atmosphere) of Earth? Would it approach a maximum value?
My intuition tells me that all around the Earth the ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.