0
votes
2answers
46 views

How to show state functions are perfect differentials, or vice-versa?

Suppose a variable $z$ is a function of two independent variables $x$ and $y$. Now, if z can be expressed in its total differential form as $$dz=Mdx+Ndy$$ Then show that $z$ is a state function iff ...
1
vote
0answers
14 views

Derived Geometry and Deformation Quantization

Can anyone please explain to me in layman' terms what derived geometry deals with and what deformation Quantization is? I have only a good understanding of Relativity,Classical Mechanics.
1
vote
1answer
27 views

Magnetic field in two different medium

From Faraday's law of induction we know if we have a coil with ac current it will create ac current to other coil placed within magnetic field. My question is if one coil is in water and another coil ...
0
votes
1answer
24 views

Calculation Equivalent Resistance In A Circuit With resistances connected in a circle

I am having trouble in finding the equivalent resistance between the terminals 'a' and 'b' in the following circuit: Please can anyone explain to me how to solve such problems. Thank You!
0
votes
0answers
23 views

Why do we see discrete light spikes coming out from a light source?

When we look at a light source from a distance in suitable darkness, why do we see discrete light spikes coming out of source like Fig. b of above picture instead of Fig. a?
0
votes
2answers
45 views

The Vectors in $v=f\lambda$

We are learning about waves in physics and I was just wondering what are the vectors and what are the scalars in this function:$$v=f\lambda$$ I know the velocity $v$ is a vector so that means that: ...
1
vote
1answer
26 views

In 2D CFT, is there a name for a field with the following OPE?

A primary field $\mathcal{O}(w,\bar{w})$ with weight $(h,\bar{h})$ has the following OPEs with the stress tensor: $T(z)\mathcal{O}(w,\bar{w})=\frac{h\mathcal{O}}{(z-w)^2}+\frac{\partial ...
1
vote
0answers
19 views

How can you find the $u$ using time dilation if you only know $\Delta t_o$?

I've come across two problems dealing with time dilation now that ask how fast should an astronaut go in order to travel EG: 400 LYears in 10 Years. What I can not wrap my head around is how this is ...
1
vote
1answer
24 views

A couple of questions regarding work to velocity exchange

I was tasked to express the velocity of the cube of mass $m$ at point B using the constants given in the picture below. Friction could be ignored, and the cube could be presumed to reach B with the ...
0
votes
1answer
25 views

Relation between homotopy theory and symmetry transformation of the Lagrangian

What is the relation between the symmetry transformations of the Lagrangian and homotopy theory? If yes, how? Not sure if this is a math or physics questions. References would be very helpful.
0
votes
1answer
19 views

Magnetic field of a current carrying wire reduce/increase exterior magnetic field?

If we place a wire within a uniform exterior magnetic field ($B_x$) that's perpendicular to it's length, and allowed current to flow withing the that conductive medium, there is another magnetic field ...
0
votes
2answers
45 views

Is the video “How to Reveal Subatomic Particles at Home”'s explanation of its experiment misleading?

https://www.youtube.com/watch?v=wN_DMMQEhfQ The video asserts that along the path of an electron or muon, a trail of condensation will appear. But from what I understand, if an electron or muon (both ...
0
votes
0answers
33 views

Undergraduate Physics Senior Research Topic (Theory/Mathematical Physics Based)

This is most likely a question for those who have experience/knowledge of theoretical/mathematical physics at the graduate level and can provide recommendations following my criteria. Here is some ...
1
vote
2answers
20 views

Why is the electric potential of a point from a point charge of +Q positive?

According to the formula, $$V = - \int \vec E \cdot d\vec r.$$ The electric potential of a point charge is $\frac{KQ}R$? However, when I perform the integration, my answer is $-\frac{KQ}R$. Since ...
-4
votes
2answers
23 views

Problem - Escalator [on hold]

I need help in resolving the following problem: On a recent weekend, Anna was rushing through a shopping centre doing her shopping she had occasion to use the escalator 3 times. The first time the ...
1
vote
0answers
16 views

ferromagnetic and Curie temperature. Energy question

Is energy absorb and release back when a ferromagnetic material heats and cools passing through the Curie temperature?
1
vote
1answer
32 views

Energy of electromagnetic wave

Its given here that energy density of an electromagnetic wave is $$\vec S=\frac{1}{\mu}(\vec E\times\vec B)$$ How is the above expression derived? And when did energy become a vector? I though work ...
1
vote
2answers
21 views

Why use vectors to describe velocity/force/etc instead of treating magnitude and direction as separate values?

I'm only 4 weeks into my first college-level physics course, so this is a very elementary question. Also, in asking this question, I'm just playing devil's advocate in order to better understand the ...
0
votes
1answer
82 views

How can space and time occur spontaneously?

In the book: "A universe from nothing" by the theoretical physicist Lawrence Krauss he mentions that space and time can occur spontaneously. Unfortunately he does not explain how. So my question is, ...
4
votes
2answers
30 views

Acceleration of a car on Earth and on the Moon

Suppposing the same enviroment conditions and without considering the air friction a car at the start of a race would have a greater acceleration on Earth or on the Moon, or would the accelerations be ...
-2
votes
1answer
64 views

Is climate change caused by humans? [on hold]

Some people argue it is not because it is caused by solar cycles (sometimes the sun brights more than others thus increasing the Earth's temperature) and that the energy that $CO_2$ traps isn't enough ...
-2
votes
1answer
40 views

Bohr radius question

I'm doing a homework problem where it asks to calculate the diameter of a hydrogen atom with $n=600$. I used the equation $r=\frac{n^2a_0}{Z}$ where $a_0=0.529e^{-10}m$. Solving for $r$ yields: ...
-1
votes
1answer
23 views

Where are the electron exchanges happening in solar cell physics when considering the photon?

When considering solar panel physics, are we taking an electron from Light(photon), or is the energy of Light causing an electron to jump in said solar cells through excitation? Is the photon even ...
1
vote
0answers
18 views

Quantum GCD circuit: Clearing ancillae

I am currently trying to implement a circuit for computing the greatest common divisor in the Quantum Computing Language. In my work, I partially proceed from the paper Quantum Circuits for GCD ...
0
votes
1answer
32 views

The question of the protein and the ribosome

It is well known that proteins are spit out by ribosomes by reading the DNA that goes in. Now ribosomes are made of proteins. Doesn´t this mean that the riobosome structure came before the production ...
1
vote
0answers
26 views

Relativity Mapmaking in spacetime

The problem as stated: I do not know how I am supposed to map this. The instructions don't make sense to me and the textbook is really un-helpful. This is the map that I have to draw this on. I ...
0
votes
0answers
10 views

Black hole starship: Would micro black-hole Hawking radiation emit anti-matter?

My understanding of Hawking radiation is that virtual particle pairs of matter and anti-matter are created from vacuum energy and one of those virtual particles may escape while the other enters the ...
1
vote
1answer
67 views

Light is/produces a electromagnetic wave, but is the opposite also true?

A similar question has been asked, and to some extent the answer is: you need an antenna with $L \approx 200nm$. But it's not entirely clear to me if this is completely hypothetical, as "Marek" also ...
0
votes
3answers
40 views

How do free electrons conduct heat in a metal?

In a metal, how do free electrons conduct heat? Does the specific heat of a metal should be then related to the electrons and not the atom of the metal?
0
votes
0answers
48 views

On the Pauli Principle

Consider a quantum mechanical system as shown-say a piece of metallic conductor in the shape of a long, thin bar.(Must it be a single crystal to be considered a "system"?). Now focus on two free ...
0
votes
1answer
18 views

Simple Harmonic Motion given velocity and acceleration

I am trying to understand how to relate velocity and acceleration of an object to it's amplitude, period, and frequency given only the following: An object of mass m=20kg moves with SHM along the ...
0
votes
0answers
14 views

finding work done by the buoyant force on a submerged object [on hold]

A flotation device is in the shape of a right cylinder, with a height of 0.500 m and a face area of 4.00 m2 on top and bottom, and its density is 0.320 times that of fresh water. It is initially held ...
1
vote
2answers
58 views

How is refractive index related to the density of a medium (for example, air)?

I have a question regarding refractive index dependency on the density of a dielectric, specifically air. Background Let us start from Newton's second law form of driven harmonic oscillators ...
1
vote
0answers
26 views

Does a set of eigenvalues in QM correspond to a random variable in statistics? [duplicate]

In quantum mechanics the possible outcomes of a measurement of a quantity corresponding to a linear hermitian operator $A$ are only the eigenvalues $a_i$ of $A$ (see e.g. ...
2
votes
0answers
31 views

Decoherence and interpretations

With quantum decoherence, are there still any "gaps" in our knowledge of quantum mechanics that hint (either in terms of the physics, philosophy, or otherwise) at the need for further interpretation? ...
1
vote
1answer
49 views

Which of the properties of particles are intrinsic properties and why?

For macroscopic objects it's clear that - once observed - the observed property does exist for a while, even if we are no longer observing it. That has to do with the complexity and stability of such ...
1
vote
1answer
17 views

Why is a series resistor needed in a simple thermistor experiment?

I have come across the following simple question, however I can't see any need for a fixed resistor in series. The only possible reason that I can think of is that the resistance of the thermistor ...
1
vote
0answers
19 views

What are these cycles in orbital eccentricity called?

I have created a simulator for planetary systems. When I run it with our own solar system and plot the eccentricity, aphelion and perihelion of the orbit of Earth i get these cycles. Do these ...
-5
votes
0answers
48 views

New time theory? [on hold]

Without having big pretentions, in these few pages I will try to describe my views concerning time, speed, movement and the interesting (to me) conclusions, to which I have come to. First, let us ...
0
votes
0answers
22 views

Calculate the Bohr radius of a muonic atom

I want to better understand this problem and how to calculate the Bohr radius. The equation I found in my book is $r_n=\frac{n^2 \hbar^2}{mkZe^2}=\frac{n^2a_0}{Z}$. However, I found a problem online ...
0
votes
1answer
38 views

Differential derivation based upon time and space confusion

I have been doing a lot of derivations recently involving heat transfer. I was attempting to derive heat accumulation in a differential element based upon inflow and outflow as well as thermodynamic ...
0
votes
2answers
41 views

How can I clarify the difference between free falling and Newton's law?

After I have viewed two experiments the first about Newton's law which involves a brick block and feather letting them fall one time in a vacuumed room they fall at the same time and another time in ...
0
votes
1answer
24 views

Methods to solve a vapor pressure equilibrium question with water on the moon?

"Imagine a tall column of water on the Moon, maintained at a temperature of 50°C and left to the open vacuum at the top. Up to what depth will the water continue to boil? The Moon's radius is 0.273 ...
0
votes
1answer
29 views

Orbital angular momentum eigenstates in the $|\mathbf{r}\rangle$ representation

Consider the orbital angular momentum operators $L^2$ and $L_z$. In the $|\mathbf{r}\rangle$ representation using spherical coordinates those operators actions are given by ...
-1
votes
0answers
17 views

P-N Junction - (Depletion Region) [duplicate]

Will i have simple q ,,, Why the electron in N Type don't go to the Formed Positive Ions ?
1
vote
1answer
47 views

How the sun can burn that long? [duplicate]

I suddenly became curious that why the sun doesn't burn out at once? What makes the sun burn gradually?
0
votes
0answers
22 views

Pure State Entanglement and Private Communication

My question is about the relation between two protocols of transmitting a quantum message through a Quantum channel using entanglement (entanglement Transmission or generation for this question) and ...
0
votes
0answers
30 views

How did I get these strange electric shocks?

While doing experiment on designing & fabricating temparature controller circuit using a thermistor, this strange thing happened.Me & my friend frequently experienced short pulses of electric ...
0
votes
0answers
11 views

How to restict air flow without reducing pressure

I have a large volume of lightly pressurized air say 10000 cubic feet at 1 psi above atmospheric pressure. I want to move it to another area through a duct which is 20 in by 20 in. Airflow will be ...

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