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From De Broglie's equation $$\lambda=\frac{h}{mv}$$
We can see that $\lambda$ depends inversely on $m$
My question is:
If the $m$ in the equation indicates the kinetic mass of the body then from this relation$$m=\frac{m_0}{√(1-v^2/c^2)}$$ $m$ would increase with $v$. Thus the $\lambda$ value should change doubly...firs... | stackexchange-physics |
Consider the following theory in which a $2$-form field $B_{\mu\nu}$ with field strength $P_{\alpha\mu\nu}=\partial_{[\alpha}B_{\mu\nu]}$ is coupled to a $3$-form gauge field $C_{\alpha\beta\gamma}$ with field strength $F_{\mu\alpha\beta\gamma} = \partial_{[\mu}C_{\alpha\beta\gamma]}$.
$$
\mathcal L = 12 m^2(P_{\alpha\... | stackexchange-physics |
In his String Theory Vol. I book, Polchinski wants to compute the string spectrum when $k$ of the 26 dimensions are compactified $$X^m \sim X^m + 2 \pi R, \quad 26 - k \leq m \leq 25 \, . \tag{8.4.1}$$
To do so, he gives two derivations, the first one being
In the canonical approach, focus on the zero-mode contributi... | stackexchange-physics |
For free particle solutions in a box, the following 4 solutions are possible(Not all 4 are independent though) as
$$\psi_+=A_+ \exp{\frac{i}{\hbar}(px-Et)}\\\psi_+^*=A_+^* \exp{\frac{-i}{\hbar}(px-Et)}\\\psi_-=A_- \exp{\frac{i}{\hbar}(px+Et)}\\\psi_-^*=A_-^* \exp{\frac{-i}{\hbar}(px+Et)}$$
where $E>0$. The properties o... | stackexchange-physics |
Here's a question I got in my final exam this morning. "If in Young's double-slit experiment setup, the ratio of the intensity of the bright spot to the dark spot is 25:9, what is the ratio of the width of the slits?"
Here's what I did. Since the ratio of intensity at the bright and dark spots is 25:9, the ratio of amp... | stackexchange-physics |
The equation
$$TdS=dU+PdV$$
is a combination of
$$dQ=dU+PdV$$
and
$$TdS=dQ.$$
But in some process that is very irreversible, $TdS>dQ$, should we write
$$TdS>dU+PdV$$
instead of the first equation? I guess the equation is different for reversible and irreversible process.
| stackexchange-physics |
I've read several QA here:
Is coherent light required for interference in Young's double slit experiment?
Why can't we duplicate the double slit experiment with two parrallel sources of light.. why must the light enter the two slits externally?
Why don't two identical monochromatic lamps form interference patterns?
Why... | stackexchange-physics |
Consider the metric corresponding to the Schwarzchild solution. It represents a Non-rotating Black hole. When we want to understand the causal structure of the spacetime we find the null geodesic equation.
Outgoing radial null geodesic - The outgoing null geodesics are drawn in region r>2m and r<2m. For r>2m, the null ... | stackexchange-physics |
Inspired by last week's solar eclipse, I'm wondering under what conditions one can see a total solar eclipse from the ISS. How often does it happen? I guess it doesn't last very long because of the fast orbital speed.
| stackexchange-physics |
In general relativity, can the differential Bianchi identity be interpreted as "non existence of gravitomagnetic monopoles"?
This was suggested by Avantgarde's answer in What is the geometric interpretation of the Einstein tensor $R_{\mu \nu} - \frac{1}{2} g_{\mu \nu} R$
The idea seems intriguing and kind of makes se... | stackexchange-physics |
In a calculation of a Lagrangian density $$
\mathcal{L}=\bar{\psi}\left(i \gamma^{\mu} \partial_{\mu}-m+i \gamma_{5} m^{\prime}\right) \psi.
$$
In order to see if it is invariant or not with the transformation,
$$
\psi(x) \longrightarrow e^{-i \beta \gamma_{5}} \psi(x) \quad \text { e } \quad \bar{\psi}(x) \longrightar... | stackexchange-physics |
As the charge would flow to/from the watch, assuming I'm insulated from the ground with rubber soles, or standing on glass.
| stackexchange-physics |
I work in a general-purpose, commercial office building where the first floor is dedicated to an x-ray / imaging lab for medical diagnostics. The public lobby of this building is routinely experiencing radiation level increase from 0.10 uSv/h (Background) to 0.96 uSv/h in approximately 20 - 30 second intervals as measu... | stackexchange-physics |
Say I try to find the magnitude of the electric field at any point within an insulating solid sphere. I know that in the case of a conductor, the electric field within it is 0. However, I have not learned anything about an insulator, so I assume that it would not be 0.
I used Gauss' Law and calculated the charge of the... | stackexchange-physics |
How would one represent a 3-D wrapping object as outlined in the linked article, Classic JRPG Worlds Are Actually Donuts? In short, it explained that to achieve the x-axis and y-axis wrap that is common in games, that world would have to be a torus.
One of the ideas I've heard about the edge of the universe is that is... | stackexchange-physics |
I do not completely understand, why do we consider Hamilton–Jacobi equation $H(q,p)=E$ as equation of motion, whereas it is looks like energy-conservation law?
| stackexchange-physics |
How would I find the force it takes to the table to tip over if you were sit on top the cantilever end?
| stackexchange-physics |
Good morning, my question is very specific and at the same time very general. How can I understand from a lagrangian density if a field is physical or unphysical. How can I make it evident from the expression of the Lagrangian?
Let me make an example. Let $\phi_1$ and $\phi_2$ be two real scalar fields, with Lagrangia... | stackexchange-physics |
A permanent magnet (cylindrical) of length (l) and radius(r) with velocity v(t) along z-axis as shown in the figure. I am looking for analytical expression for the induced emf in a coil with N turns, due to the motion of a permanent magnet.
| stackexchange-physics |
I am trying to understand the concept of a polarisation of a plane wave. Generally, the plane wave can be seen as a sum of two orthogonal linearly polarized waves. according to Wikipedia.
So I have started with a solution of a wave equation. $E_1$ and $E_2$ are two polarized waves, and the $E=E_1+E_2$ I have gotten as ... | stackexchange-physics |
If I have a planet orbiting the Sun (assuming circular orbit) at angular velocity $\Omega$ and rotating about its axis at $\omega$. I also have a normal to the surface of the planet $\vec{n}_{\rm surf}$, the normal to the orbital plane $\vec{n}_{\rm o}$, and the direction to the Sun from the planet and a normal to the ... | stackexchange-physics |
I don't know much about the unit of measure pascal to estimate the performance of a vacuum pump.
On a vacuum pump, it says that it can reach the pressure of $3\times10^{-1}\,\mbox{Pa}$. I've been trying to find out if it has a strong vacuum.
The pump I have currently have at the moment is rated at $5\,\mbox{Pa}$ and I ... | stackexchange-physics |
In my professor's lecture notes, I came across the next approach of studying non-linear waves in fluids. So we have compressible Navier-Stokes and continuity equation in 1D and we assume adiabatic ideal gas. After linearizing them about some stable point ($\vec{u}_0 = 0, \rho_0, p_o $), we get linear waves equations an... | stackexchange-physics |
I am following Marion Thorton.
It says as Galilean transformation $x_1'=x_1-vt $ is known to be wrong, we get $$x_1'=\gamma (x_1-vt) $$
Why are we assuming this?
What is the physical meaning of this assumption?
Why can't we derive the whole Lorentz transformation based on Einstein's
$2$ postulates?
| stackexchange-physics |
The Lagrangian with Lagrange multiplier in the form
$$L= T- V + \lambda f(q, \dot{q},t).$$
But there are different ways of writing the constraint $f = 0$.
Will that lead to different EOMs?
Let me give an example:
A pendulum with mass $m$ and length $\ell$.
We can use let
$$I=\int_{t_0}^{t_1}\left[\frac{1}{2}m(\dot{x}^2... | stackexchange-physics |
So, consider the theoretical situation in which the earth is no longer spinning, and we want to spin it up by running in the opposite direction (Yes, this question was inspired by the Nike commercial). Suppose that you have enough people running that you could do it in a reasonable amount of time, and that they could a... | stackexchange-physics |
In the article "Thermal Memory: A Storage of Phononic Information
Phys. Rev. Lett. 101, 267203 – Published 29 December 2008" it's said that a thermal memory need a thermal bath, similar to a power supply in electronic memory, to avoid that thermal fluctuations destroy the memory.
How does a thermal bath prevent that t... | stackexchange-physics |
I did an experiment in which small canisters (image attached) containing water, were wrapped around with colour papers of different colours were kept under the Sun (image attached)
.
The different colours were red, green, blue, orange, yellow, black and white? The water in the canister with black paper heated up the m... | stackexchange-physics |
Perovskite's material parameters? What are the major material parameters being investigated? [For example, water solubility, absorption characteristics, surface energy etc]
| stackexchange-physics |
I was reading this interpretation from this site, where these lines are noteworthy enough to talk for the fact that this interpretation doesn't actually talk about many-worlds:
These are the "many worlds" in question, although it should be clear that the label is somewhat misleading. People sometimes raise the objecti... | stackexchange-physics |
In classical mechanics, one intuitive formulation of chaos/ergodicity (in the loose sense) is that most trajectories should fill up phase space densely over infinite time. A classic example of such a system is the Sinai billiard.
In classical field theory, the phase space becomes infinite dimensional, consisting of fi... | stackexchange-physics |
Recently, I was calculating this observable:
$\langle p s|\bar\psi(0)\gamma^{\mu}\psi(0)|ps\rangle$
Where we only consider the QED case. $\psi$ corresponds to massless Dirac fermion field, p is the fermion momentum, and s is the helicity.
There are three Feynman diagrams associated with this observable in one loop leve... | stackexchange-physics |
(This is not a homework question!)
An experimental set up shows 2 rigidly placed stands, with pieces of metal links joining with each other forming a chain. The chain is hung from the top point to point of the stand.
If we were to plot a graph, with $d$ being the dependent variable and the number of links we put into... | stackexchange-physics |
While solving a numerical, I learnt this data:
take resistance of bulb filament as $1200 \Omega$ and resistance of electric heater coil as $100 \Omega$.
My question is if both bulb and heater are designed to produce heat (considering light to be a consequence of heat) then why is there a difference in their resistanc... | stackexchange-physics |
Say there is a horizontal rod, where a force $P$ is applied to the right hand side of the rod to drag it horizontally to the right. If I drew a force diagram, I'd put some vector with a length of $\| \mathbf{P} \|$ coming out of the right end of the rod. In actuality, if the rod is composed of ten particles, then is $\... | stackexchange-physics |
In this question I asked about gravity and in the answers it came up that the magnitude is equal (of the gravity acting on the Sun and the of the gravity acting on the Earth)
Does magnitude simply mean it's strength?
| stackexchange-physics |
I have studied that when a light enters from space into earth atmosphere it experience atmospheric refraction many time due to different atmospheric layer.
Then why we take sun rays parallel?
They have to be zigzag or diverging and converging at random angles? In other case why we take rays from star as zigzag eventhou... | stackexchange-physics |
im doing a project that requires me to understand how cars move. from what I understand , its the friction that is creates in the tires that enables the tire to rotate, which then push the car forward. the velocity of the car also depends how much torque is generated by the axle that is connected to the wheel. what I d... | stackexchange-physics |
For people who don't know what Sodastream is: SodaStream is a system where you can make your own soda at home using regular water and a CO2 cartridge. You put water in the special Sodastream bottle, connect it to the $\rm CO_2$ cartridge and pressurize to the target pressure. CO2 gets into the water and soda happens !
... | stackexchange-physics |
According to The book Statistical mechanics by Pathria, The Bragg-William approximation states that "the energy of an individual atom in the given system is determined by the (average) degree of order prevailing in the entire system rather than by the ( fluctuating) configurations of the neighboring atoms" What is the ... | stackexchange-physics |
My textbook goes on explaining variations of photo current/stopping potential and frequency/intensity of the light used.
My doubt is what effect does the amplitude of light wave have on photo current and stopping potential?
| stackexchange-physics |
I have seen many answers like: because we don't have infinite energy, because of gravity, because it is impossible, because of physics.
But they don't really answer my question.. I mean if there is no friction and at some points, even if just in theory, you could be so far away from other objects or at the right distan... | stackexchange-physics |
Any ideas on what it means to 'describe and explain the variation of the vertical component of the ball as it travels towards the ground'?
I dont need answers but instead a way of answering (answers wouldnt go amiss tho)
(A-Level Question)
Thanks
| stackexchange-physics |
What is the difference between the Franz-Keldysh effect and free carrier absorption? My first guess to this is that the Franz-Keldysh effect involves a bandgap potential of non-zero volts D.C. while the free carrier absorption effect involves a bandgap potential of zero volts. Obviously, this distinction is very simpli... | stackexchange-physics |
Why does Mother Nature allow bound states in arbitrarily weak attractive potential in 2D but not in 3D?
See, for example, this article, arXiv:math-ph/0208011.
| stackexchange-physics |
How much energy and heat were produced by the big bang? I'm reading Bill Bryson's Short history.... He mentioned a point that to forage light elements like hydrogen, helium and lithium into elements like carbon, oxygen, it requires kind of heat and energy of a big bang.
Can't we artificially make a carbon atom out of h... | stackexchange-physics |
I have read that we can charge a capacitor using a battery, but can the vice versa happen? My project needs to show a battery being charged through a fully charged capacitor.
| stackexchange-physics |
How do different electron microscopes avoid just scanning the atoms between the probe and the surface of the object that is actually being scanned?
| stackexchange-physics |
Neutrino oscillations indicate that neutrino have little bit mass. Among three neutrinos - electron, muon and tau neutrino - which is heavier? What is the mass range of these neutrino?
| stackexchange-physics |
Suppose I charge a sphere and leave it in vacuum for 10 years. After that time, I want its surface charge density to be in the order of 10^5C/m^2. Would that be possible? Would it depend on the material used and how? Would adding or removing electrons make a difference (positively vs negatively charged)?
| stackexchange-physics |
I found a paper by A. Belopolsky : "Picture changing operators in supergeometry and superstring theory" where he says there exists a possible physical state in one picture that doesn't exist in another picture. What A.B. does is essentially defining the picture formalism on the BRST complex and the de-Rham complex sayi... | stackexchange-physics |
What conformal transformation can I make to 2d Minkowski with metric $ds^2=-dt^2+dx^2$ to show that it is conformal to a cylinder?
| stackexchange-physics |
In the book of Classical Mechanics by Goldstein, at page 20, it is given that
However, I cannoot understand from what has been presented so far that when the constraints are not holonomics, why is it not possible to find such $q_i$s that $\delta q_i$s are independent of each other ?
| stackexchange-physics |
uniform motion means equal distance in equal intervals of time. Suppose, a particle travels on a straight line with constant acceleration, than can we say, in this case, uniform motion can be equal displacement in equal intervals of time instead of equal distance in equal intervals of time?
| stackexchange-physics |
What is forward scattering? If it is equivalent to no scattering, then why not call it "no scattering"?
| stackexchange-physics |
In the book Principles of Lasers by Orazio Svelto in chapter 8.4 there is an equation 8.4.30. I tried to understand how this formula was derived, but I couldn't figure it out. Then it evolved into 8.4.31, which also confused me.
| stackexchange-physics |
The simplest non-trivial system is a two-level system. Classically, it is a system which can be in one state labelled $H$ or another state labelled $T$.
There is no necessary reference to any particular physical system when thinking abstractly about this system and its observables, yet once we have, we can use it to de... | stackexchange-physics |
In the book of The First Three Minutes by Weinberg, at page 21, he talks about how do astronomers measure the speed of a luminous body along the line of sight by Doppler affect, i.e. the fractional change in the wavelength of the incoming light will be proportional to the speed of the body to $c$, but to use this techn... | stackexchange-physics |
The effect of gravitational waves in transverse traceless gauge on matter is represented by the expansion and contraction of a ring of test particles in the direction of polarization of the wave.
This result is obtained by choosing a gauge which in GR is a choice of a coordinates.
Does that mean that choosing another ... | stackexchange-physics |
When I was studying the Harmonic Oscillator using the Schrödinger equation, I was told in lectures to pay attention to the units.
There were 2 different equations given for the Energy of a Harmonic Oscillator:
$$(n+\frac{1}{2})h \omega$$
$$(n+\frac{1}{2})\hbar \omega$$
The trouble is that I can't understand the differ... | stackexchange-physics |
We know that we can obtain stress from strain energy density and deformation gradient, for example:
$$\mathbf P=\frac{\partial W}{\partial \mathbf F}$$
However, is there a way to calculate $W$ from $\mathbf F$ and $\mathbf P$? (Of course, we could also use other stress/deformation measures such as Cauchy stress, 2nd Pi... | stackexchange-physics |
I am referencing to a passage on wikipedia's page about AdS space:
Because the conformal infinity of AdS is timelike, specifying the initial data on a spacelike hypersurface would not determine the future evolution uniquely (i.e. deterministically) unless there are boundary conditions associated with the conformal inf... | stackexchange-physics |
I read that a straight current carrying conductor generates magnetic field around it in form of concentric circles. If so, where would be the poles of this field.
| stackexchange-physics |
I'm not a physicist but I ran across reports on the web of a so called over unity or free energy device that has been created that supposedly works.
It's called the QEG. Does this seem legit or is it yet another failed attempt to prove that free energy exists?
Of course this goes against the 1st law of thermodynamics. ... | stackexchange-physics |
I feel like this looks like a homework question, but I am out of uni for a while now. Just asking this for curiosity.
Suppose there are 2 boxes, one stack above the other. Now often I see on the internet to ask what is the static friction between the two boxes.
What I am curious about is the static friction between the... | stackexchange-physics |
Suppose the bob of a stationary pendulum is given a sharp hit to impart it some horizontal speed. Now what are the conditions for the string to become slack after rotating a particular angle?
resultant centripetal force should be zero.
-tension in the string should be zero
Or what?
And when the string becomes slack, ... | stackexchange-physics |
What does it mean the "easy-plane"?
Also, may I ask you to give me a representative picture of the easy-plane antiferromagnet?
What is the difference with the easy-plane "canted" antiferromagnet?
Thank you very much in advance!
| stackexchange-physics |
According to the Wikipedia page on many-body Green's function, since the spectral density $\rho$ obeys the sum rule
$$
\int_{-\infty}^{\infty} \frac{\mathrm{d}\omega}{2\pi} \rho(\mathbf{k},\omega) = 1,
$$
the retarded Green's function given by
$${\displaystyle G^{\mathrm {R} }(\mathbf {k} ,\omega )=\int _{-\infty }^{\... | stackexchange-physics |
Problem
A charged metal sphere of radius $a $ gives rise to a $\mathbf{D} $-field given by $\mathbf{D}=\mathbf{a_R} \frac{C}{R^2} $ in the surrounding medium with permittivity $\varepsilon $. What is the polarization surface charge density at the spherical surface $R=a $?
Attempt
We know the relationship $\mathbf{P}... | stackexchange-physics |
In the given question as in photo we are asked to calculate heat involved in isenthalpic process. Since isenthalpic means ΔH = 0 and we know enthalpy is the heat content at constant pressure.As in the question, pressure is constant then why answer not option (a) but (b). I must be wrong in Terminology. I think heat i... | stackexchange-physics |
The solutions to the time independent Schrodinger equation for a periodic potential are Bloch waves of the form
$$\psi(r) = u(r)e^{ik.r}$$
where $u(r)$ is a periodic function with the same periodicity as the potential, and $k$ is the crystal wave vector.
At a given temperature, the crystal is vibrating due to its therm... | stackexchange-physics |
Does my question make any sense?
Context: The capacitor is charged with charge $Q_0$. There is a magnetic field $B=B_0 \hat{z}$ perpendicular to the monitor's screen. The length of the (AB) wire is $\ell$. There is no friction.
Goal: I am trying to calculate the velocity of the (AB) wire. From the 2nd law of Newton, ... | stackexchange-physics |
Consider the massless Klein-Gordon equation of the form
$$\Big( \square_g - \xi R_g \Big) \phi \enspace = \enspace 0 \tag{1} \quad , $$
where $\square_g$ and $R_g$ are the d'Alembert operator and the Ricci-scalar-curvature with respect to the metric $g$ and $\xi$ is some constant. The case $\xi = 1/6$ is conformally in... | stackexchange-physics |
I'm quite surprised by these regularly spaced rings of alternating brightness in a fluorescent tube. These are also moving along the tube and only appear when the voltage is low. What are these and does the pattern have anything to do with AC frequency?
| stackexchange-physics |
In "Our Mathematical Universe" Tegmark claims that inflation theory implies the existence of an infinite set of universes.
My simple question is: what kind of infinity, and why that kind ?
I am not sure whether the amount of universes at any point in time is infinite in this model, but supposing that that amount is inf... | stackexchange-physics |
My teacher gave this question as homework while we were learning Elasticity in class.
Question description:
Objective:
To find the total elongation in the frustum as well as the potential energy stored in it.
Given:
Young’s Modulus of the frustum, $Y$
Height of the frustum, $L$
Smaller radius, $r₁$
Larger radiu... | stackexchange-physics |
We know thanks to Newton that:
$$F=G\frac{m_1\cdot m_2}{r^2}$$
Where $G$ is the Gravitational Constant that is about $6.673\cdot10^{-11}$
$m_1$ and $m_2$ are the masses of two different objects
$r$ is the distance between them.
We also know that $F=ma$ so can we write this? :
$$ma=G\frac{m_1\cdot m_2}{r^2}$$
If so what... | stackexchange-physics |
Suppose, say, I have the following wave function
It represents the wave function of a free particle.
I would want to calculate the probability of finding the particle with energy ħk and energy 2ħk. However, how do I do this?
| stackexchange-physics |
It's often said in grade school level physics books that an iron will concentrate magnetic field lines.
How can this fact be inferred from Maxwell's equations?
| stackexchange-physics |
I recently read a book of introduction of the rotational motion, but I do not quite understand the way author analysed the problem.
Situation: A light rod rests on a pivot passing throughout its centre of mass A, force $F
_1$ acts vertically down on the rod to the right of the pivot point at a distance $x_1$ from the p... | stackexchange-physics |
Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?
| stackexchange-physics |
Let $P\to M$ be a $G$-principal bundle, $G$ a topological group, $\omega$ the connection and $V$ a vector space.
We define $d_\omega: \Omega^k_G(P, V)\to\Omega^{k+1}_G(P, V)$ the exterior covariant derivative such that for a vector-valued differential form $\alpha\in\Omega^k_G(P, V)$, we get $d_\omega\alpha=d\alpha+\om... | stackexchange-physics |
I really don't understand the input-output formalism. I've gone through the 1985 paper, and I get completely lost when the following formula is written:
$$b_{out}(t)-b_{in}(t) = \sqrt{\gamma} c(t)$$
To quote the paper:
"We specify the input $b_{in}$ and solve 2.12 [the quantum langevian
equation], for a(t). We then co... | stackexchange-physics |
The wikipedia page for String Theory lists $\text{SO}(32)$ and $\text{E}_8\times \text{E}_8$ as group symmetries of some of the string theory types, and the page on $\text{E}_8$ says:
$\text{E}_8\times \text{E}_8$ is the gauge group of one of the two types of heterotic string
Am I to infer from this that these string... | stackexchange-physics |
A dopant with 5 valance electrons is added to a semiconductor (with 4 valance electrons), but now the dopant has 9 electrons in its valance shell. An atom requires only 8 electrons but has an extra one (8+1). How does Chemistry react to this?
| stackexchange-physics |
I am having trouble understanding the following calculation from a textbook on symmetry:
There, the Higgs potential is defined as $V(\Phi) = -\rho^2 \Phi^{\dagger}\Phi + \lambda (\Phi^{\dagger}\Phi)^2$ with the spin 0 field doublet
$\Phi := \begin{pmatrix}\phi_1\\\phi_2\end{pmatrix}$.
It is further stated that this ... | stackexchange-physics |
Possible Duplicate:
Basic buoyancy question: Man in a boat with a stone
A man is on a boat, in the middle of a quiet lake.
He has something in his hands (anything you like)
He throws the "something" in the water.
Does the water level increases or decreases?
And if the answer is "it depends", on what it does?
| stackexchange-physics |
I'm considering a wrist-energized gyroscope, shown below (after my daughter let it fall and it broke open). That one was sold as Roller Ball, but variants are known as Powerball, DynaBee, Dynaball, Dyna-Flex, Wrist Ball, NSD Spinner..
There are essentially 3 relatively moving parts:
the rotor (yellow) and its (metal)... | stackexchange-physics |
From what I found, the formula for calculating the energy level of an atom is:
$$ E_n=-hcR_{\infty}\cdot\frac{{Z_{eff}}^{2}}{n^{2}}$$
Where,
$E_n$ = Energy Level,
$h$ = Planck Constant,
$c$ = Speed of Light,
$R$ = Rydberg Constant,
$Z$ = Effective Nuclear Charge,
$n$ = Principal Quantum Number.
By my calculations, in a... | stackexchange-physics |
I bought this "flickering flame bulb" recently.
This is what it looks like:
https://www.youtube.com/shorts/Py7pD0Oor9o
Here is the same thing but in slightly slow motion:
https://www.youtube.com/shorts/bGrohhEwISg
I (a physics enthusiast) was talking about the bulb with my Dad (electrician) and we were arguing about ho... | stackexchange-physics |
Is there any relation between drift velocity and area velocity?
And how I can to find area velocity for electrons in a magnetic field?
| stackexchange-physics |
In order to make the Minkowski metric, in special relativity, equivalent to the Euclidean metric, one idea is to allow time to take imaginary values. As far as I have learned about SR, it does make calculations and derivations better, but I'm not sure how far can it go. I've been told by some that it does not work at a... | stackexchange-physics |
I understand that, in a given system with no external torques applied, angular momentum is conserved. However, consider the following situation:
Let's say the earth revolves around the Sun in a circle. My reference point will be one point on the circle. When the earth is, say on the other side of the circle from my ref... | stackexchange-physics |
Source: Principles of Physics by Resnick, Halliday, Walker. $9^{th}$ edition. Chapter 18. Problem 6.
On a linear $X$ temperature scale, water freezes at $-125.0^0X$ and boils at $360.0^0X$. On a linear $Y$ scale, water freezes at $-70.00^0Y$ and boils at $-30.00^0Y$. A temperature of $50.00^0Y$ corresponds to what temp... | stackexchange-physics |
In my school, I learned that when two blocks are placed on the ground with one block above the other, if a force is applied to the lower block, two opposing forces of friction act on it: one from the ground and the other from the upper block's surface. Consequently, according to Newton's third law, the upper block expe... | stackexchange-physics |
I was lately studying about the Lagrange and Hamiltonian Mechanics. This gave me a perspective of looking at classical mechanics different from that of Newton's. I would like to know if there are other accepted formalism of the same which are not quite useful compared to others (because otherwise if would have been fam... | stackexchange-physics |
My book shows this diagram in which electron moving only in magnetic field (where direction of magnetic field is out of the page) going down (after affecting by magnetic field) and hitting at point 'B'(not applying electric current/field). But according to Fleming's left hand rule the electron should go up(force due to... | stackexchange-physics |
Here is my attempt at derivation:
First you must find a vector function for the gravitational force.
By the inverse square law, the magnitude of gravitational force between two bodies of mass $m$ and $M$ of distance $r$ apart is: $$G \frac{M m}{r^2}$$
The direction of this force points towards the other body. If you le... | stackexchange-physics |
Also, if I throw an eraser on a table shouldn't it's g.p.e be $mg$ times its height from the ground, plus the additional height on the table instead of just the height on the table?
| stackexchange-physics |
If we look at objects in the universe, they form orderly structures like spheres, planetary systems, galactic spirals, etc. Is this decrease in entropy balanced by a decrease due to gravitational waves appearing during the formation of these structures? So the total of gravitational entropy decreases?
| stackexchange-physics |
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