1
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0answers
22 views

Two conductor's in a magnetic field, canceling each other's EMF?

If two conductor's are in a $\Delta$B, oriented the same in the field, and they induce equal $\epsilon$, can their wiring be oriented in a way that they can cancel each other's induced $\epsilon$? So ...
1
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0answers
45 views

Caustic airy equation and divergent series [closed]

How is the behaviour or creation or mathematical explanation of a caustic related to the divergent power asymptotic series in the limit $ x \to \infty $?
1
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1answer
546 views

Energy Dispersion in Young's Double Slit Experiment

In Young's double slit experiment, when you see the diffraction pattern, why does the intensity of the light fade out as you move from the central maximum? I think it has something to do with the ...
1
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0answers
82 views

Frequency dependance of sound wave reflection

Why are high frequencies reflected more than low frequencies off an 'acoustically hard' surface such as concrete? I basically understand that the amount of reflection is determined by the impedance ...
1
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0answers
55 views

Mixed two-point vertex in QFT

I am considering a theory with two fields, say $\phi$ and $\psi$. The Lagrangian contains quadratic terms, i.e., propagators for both fields and a quartic interaction term for one of the fields. ...
1
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1answer
290 views

Normalization of a wavefunction that's superposition of two unknown energy eigenfunctions

Question:$$\psi(x)=A(3u_1(x)+4u_2(x))$$where $u_1(x)$ and $u_2(x)$ are energy eigenfunctions. How to normalize function $\psi(x)$? My intuitive solution: I got ...
1
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0answers
99 views

Scalar Yukawa Theory in non-relativistic limit

I'm new to QFT, and am enrolled in a class at my school. I feel as though the teacher didn't give us the tools to tackle this problem yet. It's only the second week and we've gone through at most ...
1
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0answers
69 views

For thermal mass flow measurement technologies is it necessary to measure gas pressure to determine volumetric flow rate?

Mass flow readings from thermal mass flow measurement technologies often provide output readings in volumetric units (e.g. standard liters per minute). Mathematically I can derive the volumetric flow ...
1
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0answers
279 views

Change of Basis For Pauli Matrix From Z Diagonal to X Diagonal Basis

I want to find a matrix such that it takes a spin z ket in the z basis, $$ \lvert S_z + \rangle_z $$ and operates on it, giving me a spin z ket in the x basis, $$ U \lvert S_z + \rangle_z = ...
1
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0answers
40 views

Electric field of Symmetric Parts [closed]

So I'm preparing for a test and one thing that I haven't seen examples of, but know is possible is using Gauss's Law on objects that have symmetric parts. I made up the following question: Find ...
1
vote
0answers
41 views

What is the difference between the compact U(1) group and non-compact U(1) group? [duplicate]

Is compact $U(1)$ and non-compact $U(1)$ just two different representations for the same group or the same gauge theory? If not, what the difference of them? Or are there any properties that are ...
1
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1answer
221 views

Conservation of energy when focusing black body radiation on another black body

This question about whether or not it is possible to focus black-body radiation to make something hotter than the radiation's source was answered mostly negative: the second law of thermodynamics ...
1
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0answers
37 views

Mean-field approach to quantum phase transitions in Fermi systems

I have a basic confusion concerning the mean-field theory of quantum phase transitions in Fermi systems. Consider as an example the BCS theory of superconductivity in a Dirac fermion system, ...
1
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1answer
45 views

Variation of Peak Current and Peak Voltage with Capacitance in an AC circuit

The relation of Peak current, Peak voltage and Capacitive Reactance in Alternating Current is given by: $$i_m=\frac{v_m}{X_c}$$ and $$X_c=\frac{1}{C\omega }$$ So if we have a circuit with a ...
1
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0answers
78 views

How much of elastic energy is stored as entropy?

There are two cases of elastic stretching: springs and rubber. When you streach a spring or a piece of rubber both absorb some energy as Entropy (S) and some as plain energy (U) $$\displaystyle{ ...
1
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1answer
148 views

Total magnetic moment in an atom

I have a doubt regarding the calculation of total angular momentum of electron in an atom. Which is the right way to do it? Method 1: Total magnetic moment $$ \begin{align} \vec{\mu_J} &= ...
1
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0answers
23 views

Proton energy distribution after Si layer

I've been using SRIM to get an approximation of the energy distribution that a beam of monoenergetic incident ions will have after a thin layer of silicon. However, for my purposes it would be better ...
1
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2answers
501 views

How the polarization of electromagnetic wave is determined?

What help us determine the polarization of electromagnetic wave . Does perpendicular electric and magnetic field determine it or does the direction of propagation ?
1
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0answers
84 views

Question on electromagnetic wave propagation [closed]

how to do part d of this question? i have done part 1 to three but part d is bit confusing.
1
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1answer
52 views

Capacitors in Series and Parallel [closed]

I'm working on a physics project and we're disagreeing on how to analyze a circuit. I think the circuit should be $(1/c_1 + 1/c_2)^{-1} + c_3$ and other people in my group think it should be $((c_3 + ...
1
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1answer
128 views

Simple Harmonic Motion homework [closed]

Suppose we have a rod of mass $m$ and length $l$ which is pivoted at center and two springs of spring constant $k$ are attached at opposite ends so that it performs simple Harmonic motion when ...
1
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0answers
175 views

Hamiltonian for Electron in Magnetic Field with Symmetric Gauge in Polar Coordinates

I am new on the board and have a question about how to write the Hamiltonian for an electron in a magnetic field rotating at a fixed radius. I would like to write the hamiltonian using the symmetric ...
1
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0answers
60 views

Rigid body translation and the moment about a point

ok the statement of the moments , beside the fourth car image How there is a moment about the point A although there is only translational motion , is not the car only moving and not rotating ? ...
1
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0answers
18 views

Does there exists a flexible supermaterial with which you can write a “thermal image” instead of a visible light image [closed]

I'm thinking a mesh of copper that some how heats up at the touching points and you address each point with rapid switching. Would that not work? Also, what do you suggest as a heater at each of ...
1
vote
0answers
63 views

Why is this equation regarding boson coherent states true?

I'm reading the proof of the closure for boson coherent states and it involves the following step: $$ \int \prod_{\beta}\frac{\mathrm d \phi^*_{\beta} \mathrm d \phi_{\beta}}{2 \pi i} e^{-\sum_\beta ...
1
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0answers
112 views

Thermodynamics: Caclulate final temperature with hot metal in gas [closed]

I've been working on this problem for a couple of hours now, and I think that I simply don't understand the basic principles that tie into the problem: (note that I attempted this problem and it was ...
1
vote
0answers
63 views

Diffusion of particles

If $n(\vec{r},t)$ is the number of particles per unit volume and $V$ the volume, then $N = nV $is the number of particles in volume $V$ For a small volume, it should be $dN = d(nV) = Vdn + ndV$ But ...
1
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3answers
78 views

Finding charge density from from differential form of gauss law

I didnt get why he didvided and multiplied by r^2.This question is from d j griffith .
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0answers
180 views

Can the diffraction/interference pattern behind the slit (double slit) be calculated with Feynman path integrals (QED)?

I often see Feynman path integrals explained by a graphic which shows the slit and then the electron goes all possible ways behind the slit. Ok that is nice to understand the Feynman path integral, ...
1
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1answer
904 views

Flow Resistance and Pressures in Split Pipes

I am doing some simple flow experiments and my instruments are giving me strange results - I think they are broken, I need a sanity check for my understanding of the flow in my system to confirm it. ...
1
vote
0answers
30 views

Distribution of refractive index of water when applied pressure wave

I was wondering when applying pressure wave, ultrasonic sound waves, under water, how I would be able to measure the distribution of the refractive index.
1
vote
0answers
63 views

Use a Delayed Choice Quantum Eraser to communicate Faster Than Light [duplicate]

In the experiment setup picture of the Delayed choice quantum eraser, photons reach D0 and shows a pattern, before its quantum entangled counterparts reach one of D1, D2, D3, or D4. The pattern ...
1
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1answer
68 views

Reason behind the train remaining intact to the Train track

I was wondering why trains moving at such hard speeds remain intact to the railway track even while turning. Is it because of friction ?
1
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1answer
173 views

Two masses on frictionless table with one string connecting both masses on ground and the other string [closed]

From Morin's Introduction to Classical Mechanics page 342: A solid cylinder of mass $m$ and radius $r$ lies flat on frictionless horizontal table, with a massless string running halfway around ...
1
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0answers
29 views

Can anyone give me a simple proof for the sign change of electronic wavefunction when taken around a loop containing a conical intersection?

How and why does the sign of the electronic wavefunction changes when it is taken around a contour? For example, suppose the initial wavefunction is $f(s;S_0)$ at nuclear configuration $S_0$ and now ...
1
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0answers
193 views

How to show circular orbit as a precessing ellipse

A uniform distribution of dust in the solar system adds to the gravitational attraction of the sun on the planet an additional force linear in $r$ where m is the mass of the planet, k is a constant ...
1
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0answers
44 views

About category theory and physics [duplicate]

Could the ideas of category theory be applied to Physics, maybe simplifying how algebraic topology and sheaf theory and other hard-to-explain subjects are used in physics?
1
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0answers
32 views

Did the Cretaceous-Paleogene extinction event cause miniature tidal waves?

This could be considered on-topic for Earth Science, but I'm putting it here because I'm interested primarily in the dynamics of the impact. 65 million years ago, a large body crashed down onto ...
1
vote
0answers
13 views

Split property for type III algebras entails practical separability

I am reading Halvorson's thesis (http://philsci-archive.pitt.edu/346/1/main-new.pdf), however I don't understand a proof at p.50 where he tries to explain why the split property allows a local agent ...
1
vote
0answers
61 views

Divergence in interaction between induced dipoles

Suppose I have two polarizable point-particles 1 and 2 arranged on the z-axis and separated by $r$. Each particle has a dipole moment $\mathbf{p}_i=\alpha \mathbf{E}_i$. If we apply an external field ...
1
vote
1answer
33 views

How does change of pressure affect molecular rovibrational bands position and width?

Lets say I have $CO_2$ gas chamber with pressure $P_0$. How do rotation-vibrational transition bands alter when I change pressure P? Do they shift or not and why?
1
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0answers
33 views

Global Circulation Model of tidally locked planets for PC?

Is there some free simple Global Circulation Model that can handle tidally locked planets and can be easily compiled and used on a PC computer? It does not have to be very precise, I am interested ...
1
vote
1answer
36 views

Wave-like description of Compton scattering and photoelectric effect

I have found in the wikipedia page for QFT the following statement: ... Although the photoelectric effect and Compton scattering strongly suggest the existence of the photon, it is now understood ...
1
vote
1answer
120 views

Numerical error with simulation of electric charge in homogeneous magnetic field [closed]

So, I am trying to make an 2D animation of electric charge in homogeneous magnetic field which is perpendicular to charge's velocity. I've got the "circular" motion but the problem is that the speed ...
1
vote
1answer
45 views

Is every imaginable quasi-static locus (with non-decreasing entropy) physically realisable?

If I have an isolated composite system which is dependent on several extensive properties (say $U_i, V_i$ and $N_i$ for each subsystem $i$) then a quasi-static locus is just a continuous curve through ...
1
vote
0answers
69 views

Use mirror to see every angle around me

An applied physics question: How can I setup a mirror all around an arm wrestling table so I can see all angles of what I'm doing? The arm wresting table looks like this With the wrestlers on ...
1
vote
0answers
26 views

Will the background radiation get “dimmer”? If so when will it be “turned off” [duplicate]

This video http://youtu.be/_mZQ-5-KYHw talks about the background radiation which we can observe today. It's from the beginning of the universe and has traveled so long that the expansion of the ...
1
vote
0answers
32 views

If i had a aero-nautical object [closed]

If i had a aero-nautical object with a span of 10 feet and a weight of 40 pounds with a strong gale blowing do you think i could make it off a cliff with out plummeting to total utter death?
1
vote
2answers
275 views

Understanding basic quantum mechanics notation [closed]

I was talking with a guy about energy levels of an atom in a magnetic field. He said that energy levels are shifted and that, if you want know how much, you have to analyze this: for 1s state: ...
1
vote
1answer
91 views

Electric field of a finite, conducting plate

let's assume a finite, conducting plate of dimension: 10m x 10m x 1m. I want to determine the electric field at the middle of one of the plates 10m x 10m surfaces. Using Gauss's law one finds the ...

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