instruction stringlengths 31 24.3k |
|---|
In a Markov chain Monte Carlo (MCMC) algorithm, autocorrelation is a measure of correlation between subsequent measurements. This is in many cases quantified by considering the correlation between some observables corresponding to each measurement.
However, in some MCMC algorithms, such as diagrammatic Monte Carlo, one... |
I had read from several sources that electric field inside a conductor is zero. This is attributed to the fact that the electrons are loosely bound to the nuclei and they are free to rearrange themselves until the net field becomes zero.
But in an insulator the electrons are tightly bound to the nuclei. So they can res... |
In Hobson et al, General Relativity: An Introduction for Physicists (pg. 15), it was said that it is natural to describe the worldline of a massive particle by giving the four coordinates $(t,x,y,z)$ as functions of the proper time $\tau$, i.e. $(t(\tau),x(\tau),y(\tau),z(\tau))$.
Why did the author feel that it was ... |
I am getting a little bit confused with calculating moment of inertia of symetric objects.
For example if the task was to find $I$ of a thin equilateral triangular plate of mass $m$ and side $a$ about an axis through its center (perpendicular to the plane). If I divide the triangle into $6$ same parts and find the mom... |
According to the Particle Data Group, the lifetimes of the neutral and charged $\Xi$ baryons differ significantly: $\tau(\Xi^-) = (1.639 \pm 0.015) \times 10^{-10}$ s, while $\tau(\Xi^0) = (2.90 \pm 0.09) \times 10^{-10}$ s. This is despite the fact that the dominant decay mode of both is to $\Lambda \pi$ (with a charg... |
I read in a blog Quantum Entanglement: Slower Than Light that one can not force a particle from an EPR pair to have a not statistical outcome for the entanglement parameter. I can not understand why? Is it prohibited by some no go theorem?
A sort of explanation is included in Chad Orzel blog:
He writes there:
If you c... |
In the Wikipedia article on Slipstream (https://en.wikipedia.org/wiki/Slipstream ) it is said: "A slipstream is a region behind a moving object in which a wake of fluid (typically air or water) is moving at velocities comparable to the moving object".
The word "comparable", to me, creates the impression that the veloc... |
I'm studying sound, and speaker isolation solutions specifically. I keep seeing the idea that spikes reduce the transmission of vibration due to the small contact area, but couldn't find any material on how and why this is so, and what frequencies does the decoupling effect work/not work on?
If anyone could give me an... |
I know there are multiple SE questions talking about this subject but I still don't understand:
If I have three balls as seen in the picture, what is the direction of friction on each ball if:
No forces are applied on the first ball except gravity and N in the Y axis (I don't about friction, that's why I'm asking)
So... |
What Is the physical meaning of the dielectric constant ?
(I don't want the mathematical expression)
Thanks In advance.
|
How would we derive the equation for the capacitance of a spherical capacitor when the inner sphere has been earthed?
I am aware of the formula $\frac{4\pi \epsilon_0}{\frac{1}{R_1}-\frac{1}{R_2}}$ (R1, R2 are the radii of the two spheres), does that also apply when the outer sphere has been earthed?
|
I am currently looking at "Physical aspect of space-time torsion" by IL Shapiro. There in eq. 2.10, it mentions that in space-time with torsion the commutator of covariant derivatives acting on the scalar $\phi$ gives $$[\nabla_\mu, \nabla_\nu]\phi = K^\lambda_{~~~\mu\nu}\partial_\lambda \phi$$
Where $K$ is the contors... |
I'm trying to model the wave function for an asymmetric delta function potential well, in which the left side of the well is at a potential of $0$, however the right side of the well has been moved down to $-5U$. Considering free particles of energy $E_1 = -2U$ and $E_2 = -6U$, what would their wave functions look lik... |
My question is whether Peierls substitution really holds true for time-dependent electromagnetic (EM) potentials and, if yes, why.
To implement an electromagnetic field in a condensed matter system described by a Bloch Hamiltonian, I have often seen people make the following substitution of the hopping integrals
$t_{12... |
If I run two laps (= same distance) at different velocities $v_1$ and $v_2$, it is easy to derive algebraically that the mean velocity is given by the harmonic mean of $v_1$ and $v_2$
$$
\bar v_{\text{harm}} = \frac{2}{\frac{1}{v_1}+\frac{1}{v_2}} = \frac{2v_1v_2}{v_1+v_2}
$$
My question is: How can we understand the t... |
A bat is flying towards a wall while emitting an ultrasound of frequency 25kHz. Emitted sound and the sound that bounces off a wall form a beat frequency 1.65kHz, that the bat detects. With what speed does the bat approach the wall? Speed of sound is 340m/s.
This is the full exercise. The answer is:
The bat detects the... |
This is from Pierre J. Clavier and Viet Dang Nguyen's paper Batalin-Vilkovisky formalism as a theory of integration for polyvectors.
In section 2.3, it states:
A symmetry is said to be open when it is fulfilled only on-shell, that is on the critical domain of the action $S_0$, i.e. on the submanifold of the configurat... |
The equivalence principle as I understand it goes something like this:
Let's suppose you're in a black box in the middle of nowhere in space, and we accelerate this black box in some direction. You'd feel a force just like you would if you were in a gravitational field which was causing the same acceleration.
In fact t... |
Suppose we take the quantum mechanical hydrogen atom and replace the proton with a black hole. Consider the black hole to be the same mass as the proton, to be uncharged and to provide a similar gravitational attraction as the Coulomb attraction would apply in the standard scenario. How would the energy levels of the t... |
In the imdb.com goofs page of the movie Interstellar, I found this statement:
How does time dilation affect $g$-force? If this could be explained in Laymen's terms it would be much appreciated.
|
I came across this video: https://www.youtube.com/watch?v=mHsVxNMFWwA
How is this possible? I'm guessing the vertical toothpick is exerting an upward force on the table toothpick to balance the torque. But how? I am confus
|
I'm trying to understand the principle of topological insulator.
Why a band has to be isolated to have a Chern number of 1? More precisely, why, in the case of Haldane Model, all the bands in the valence band don't participate with a Chern number of 1 as in the case of IntQHE?
|
The 1-dimensional Kronig-Penney Model predicts a relationship between energy, $E$ and
wavenumber, $k$ of the form:
$$\cos(ka)=\cos(qa) - \frac{m_e\,A\,t_0\,\sin(qa)}{\hbar^2\,qa}$$
where $$q=\sqrt{\frac{2m_e\,E}{\hbar^2}}$$
and $m_e$ is the electron mass, $\alpha$ is the lattice constant, $A$ [$m^2$] is a constant, an... |
I offer my colleague some milk in her coffee. The milk has just come out of the fridge.
"Not now," she says. "Not till after I've finished my sandwich, and I don't want it to go cold."
So: identical mugs and quantities of hot coffee and milk at same temperature; only difference is that the cold milk is added
—
straight... |
Why is it that statically determinate beams can take some degree of misfits without any generation of strains or stress, but not statically indeterminate beams?
|
According to this, the size of the focal spot of sunlight through a lens is f/110, where f is the focal length. A 61" fresnel lens with 86 cm focal length then has a spot which is 7.8mm high, which is quite large. How much smaller can the spot get if you add another lens at the focal spot to focus it further and then m... |
Experimentally I know that two monocromatic beams of different colors or orthogonal polarizers do not interfere with each other (so the interference coefficient is zero). Theoretically, why does that happen? Thanks in advance!
|
In Fermi-Dirac statistic the number of states with energy between $[\epsilon,\epsilon+d\epsilon]$ is $dN=g(\epsilon)d\epsilon$ if I want to know the total number of occupied states in an atom I do this: $N=\int_{-\infty}^{\epsilon_f} g(\epsilon)d\epsilon$ where $\epsilon_f$ is the Fermi energy. Now, the number of elect... |
I recently read a derivation of electric field due to a solid conducting sphere which also included a term volume charge density. We know that charge on a conductor resides on the surface. My question is that if charge on a conducting sphere resides on the surface then why do we define volume charge density for conduct... |
I am wondering if it is possible to differentiate between pure states and mixed ones in the laboratory?
For example consider a quantum system define relative to the orthonormal basis {up,down}. We can build a mixed state which is a combination of 2 or more pure states. Then we measured the probability of the system to ... |
From Fermi's Golden Rule one can derive that the decay rate for a two-particle decay ($A\to B+C$) is given by
$$\Gamma = \frac{p^*}{32\pi^2m_A^2} \int |{\cal M}|^2 d\Omega,$$
where the absolute value of the momenta of the outgoing particles is given by
$$p^* = \frac{1}{2m_A} \sqrt{\left[ m_A^2 - (m_B + m_C)^2 \right] \... |
Well, I asked this title question to my teacher, and he told me that yes, it is true. But I couldn't quite understand how is it possible?
He gave me an example of a simple pendulum and told that it is both periodic and oscillatory. But a pendulum may not return to its mean position every time in the same time interval,... |
At $T=0K$ what's the difference between Fermi energy and first ionisation energy?
|
A 3-jet event can arise when a quark and an anti-quark are pair produced and, subsequently, one of these particles produces a gluon via bremsstrahlung.
On top of page 270 of "Particle Physics in the LHC Era", it is stated that the gluon jet usually has the lowest energy. Why is this the case?
|
I have a heater rated at 13 kW with two identical heating elements connected in parallel with a 240VAC power supply. If I connect elements in series instead what should be my expectation:
That the total resistance in the circuit will increase thereby reducing the current for the same power dissipation?
or
The power ... |
When we talk about current, we say electrons are "flowing" through a conductor. But if electrons are identical particles, how does it make sense to talk about them flowing?
To expand on that: imagine the simplest wire, just a 1-D chain of copper atoms, each with one conduction electron. If we apply a potetntial across ... |
Bernoulli's principle states that air molecules moving with high velocity create an area of low pressure which in turn causes an object to fly, but how does high velocity cause low pressure?
|
Definitions
During a lecture I was introduced to several ways of expressing "length" in the context of cosmology. Explicitly, I was given the definitons ($a$: scale factor, $c$: speed of light, $\theta$: angular size of object in the sky, $L_{\rm phys}= a L_{\rm comoving}$, $F:$ Flux, $L:$ Luminosity)
$$
\begin{array}{... |
I'm not sure in which blocks is $\vec{F}$ acting on, I know it is clearly acting on the block of mass $M$ and clearly acting on the block of mass $m_2$. I'm not certain about the effects of $\vec{F}$ on the block of mass $m_1$.
This is a problem with no friction which consists on finding $F$ with respect to the masses... |
I am an undergraduate student studying computer engineering. I love programming, especially competitive programming, and I'm very interested in Artificial General Intelligence because I really like the idea of building something that is able to think. I'm also quite interested in physics, mainly cosmology. But before I... |
Is it possible that collisions which are elastic in the rest frame of reference are inelastic or partially elastic in some other constant velocity frame? If you need to invoke general relativity here, that is also welcome.
|
I am going to be teaching an introductory university class on E&M and Modern Physics (from Coulomb's Law through Maxwell's Equations and optics, followed by a brief mention of quantum and relativity) to students in the 'life-sciences' (which, according to our department, pretty much includes any scientist who isn't a p... |
In Griffiths' Introduction to Elementary Particles (2ed), at the end of Sec 4.1, he says that
an ordinary scalar belongs to the one-dimensional representation of the rotation group, $SO(3)$, and a vector belongs to the three-dimensional representation; four-vectors belong to the four-dimensional representation of the ... |
I'm having trouble understanding an equation and solution method given in literature. The 1D flow equation for "high rate" linear gas flow through a porous medium is given as:
$$\tag{1} p_1-p_2=\Delta p = \frac{\mu L}{k \beta} \left(\frac{w}{A}\right) + \frac{c_f L}{\sqrt{k} \beta} \left(\frac{w}{A}\right)^2$$
where $p... |
The other day, a friend and I were looking at a simple resistor-capacitor-inductor circuit. As we were looking at the circuit, he mentioned that the capacitors and inductors "talked" to each other through the air. From this, I assume he meant that the capacitors and inductors were exchanging EMF waves, and that it was ... |
Physics theories are always constrained by symmetry principles (Strong equivalence principle, Galilean invariance principle, Gauge invariance, …).
This means that each model of a theory inherits (by construction) the symmetries enforced by the theory. For example, in classical mechanics, every model is (supposedly) Gal... |
I am trying to understand equation (25.91) from Schwartz's Quantum Field Theory textbook. The goal is to gauge-fix the path integral for Quantum chromodynamics using the Faddeev-Popov trick. Briefly, the argument boils down to multiplying the integral by:
$$1=C\sqrt{\det(\partial_{\mu}D^{\mu})^2}\int {\cal D}\pi~ e^{-i... |
Let us suppose we have a particle that is near the event horizon of a black hole.
The Shroedinger equation for particle without interacting with itself in a gravitational field is given as:
$$
i \hbar \frac{\partial \Psi}{\partial t} = (-\frac{\hbar^2}{2m} \nabla^2 + V(x)) \Psi
$$
Where $\Psi(x,t)$ is the time depend... |
"The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole".
Why does this happen? I mean, why something finite (like the core of a very masive star) should lead to an infinitly small point (singularity). For me it's like spacetime has a "wekness" and it breaks... |
The Copernican Principle states that Earth is not at a special place in the Universe, and by extension, that there are no "special places" in the Universe (per homogeneity of the universe, aka the cosmological principle). However, the frame in which the CMB is isotropic appears pretty special:
There is exactly one ref... |
When I insert my finger into a moving motor with a wing, when my finger collides with the wing of the dc motor, the motor stops, and when I remove my finger, the motor rotates again.
What is this phenomenon called?
Why doesn't the engine wing push my finger out?
Do you need more voltage to push my finger out of the rot... |
I realize that the imaginary evolution could help us to find the ground state for a system.
However, I very puzzled why it works, and what the principle is back up there?
I have done some searching on this, but all I could find was people using this but not talking about why.
Please explain this part to me in detail.
|
We know the universe is filled with a near uniform radiation at a equilibrium temperature(T) of approximately 2.725K. It's a remnant of the Big Bang. My reasoning to propose this question is, we can try to associate a density to this cosmic microwave background, as $E = mc^2$ (Einstein's equation).
The tricky part is t... |
If I am inside a closed liquid bottle, will I be able to hear loud noise outside the bottle?
|
Imagine I'm in an infinitely large vacuum and have a special apparatus built into my body that allows me to breath, eat, pee/poo, etc. and never age. The vacuum is similar to deep space and has no heat source or visible light and is therefore quite close to absolute zero. Perhaps we should say just above absolute zero ... |
Suppose there is a free spring (there is no mass attached to it ). Next , I apply a force "$f$" to it and extend it's length to say x from mean position. Now, I hold the spring at that position. At length $x$ the spring force (on me by spring) $= -Fx$ (-ve because directed towards mean position ) and by Newton's $3$rd... |
I couldn't find a similar question here and some answers online were contradictory so I hope that we can clear this out here.
So, does amplitude depend on mass for a mass-spring-damper system? If not, why not?
My understanding is that mass should not affect the amplitude, only the initial energy provided to the system ... |
I have a naive model of action potential energy use and I’m unsure where the model is wrong. Clearly the model is wrong because its conclusion is wrong:
When an action potential moves along an axon, it moves along the entire surface area (circumference) of the axon. Hence, in order to maintain the desired amount of vo... |
I'm having difficulty understanding why a floating capacitor will store less charge than a grounded capacitor. Imagine you have two parallel plates and a low DC voltage source like 5V, with the negative side connected to neutral ground, and that you have two different ways of wiring it:
In case 1, you connect one side ... |
In reference to this note, a specific Focker-Planck equation with initial condition $W(\rho, t=0)=\delta(\rho-1)$ have the solution
$$W\left(\rho,t\right)=\dfrac{e^{-\frac{t}{4}}}{\sqrt{\pi}t^{\frac{3}{2}}}\intop_{\mathrm{arccosh}\left(\sqrt{\rho}\right)}^{\infty}\frac{d\left(y^{2}\right)e^{-\left(\frac{y^{2}}{t}\right... |
How are angular velocity, speed and radius related to each other?
|
In my physics class, we have begun talking about potential difference, charge, resistance etc. While watching online videos for extra help on some clarification, I often hear that as electrons move through a resistor they lose some of their electric potential energy, creating a difference in voltage (v1 greater than v2... |
Imagine a Pulse of light traveling through space at $c$, coming towards an observer on Earth, while at the same time, Space-time fabric (metric) is continuously changing (expanding), then why is the speed of light constant throughout space-time, since the separation of the very two-points in space, light is traveling i... |
This question posted by me on MSE talks about a physics problem. This is what it was: (I hope someone can help me with this)
Consider a region of 2-dimensional space with a uniform magnetic field of magnitude $B$ directed perpendicular to the plane. With respect to some fixed point (origin), at a point with position ve... |
I can't understand following statement from Carroll book
[Future] event horizon can be equivalently defined as the boundary of $J^-(\mathcal{I}^+)$, causal past of future null infinity.
I made use of Penrose diagram and get the following.
I used the curly line to denote the boundary of light cones(their angle is pres... |
I was wondering if there was a way to construct the ladder operators for a nonlinear oscillator given by the Hamiltonian $$H=x^2+p^2+\lambda x^4$$ If we were to just calculate scattering amplitudes, then it makes sense to just use the harmonic oscillator ladder operators and use perturbation theory. But I am looking to... |
I'd like to know if there is a solution that allows me to measure the frequency of vibration of a surface/object. Primarily I am seeking to improve my speaker/home audio setup. The vibrometers I've found (and can afford) can give me the amplitude of vibration, speed of vibration and acceleration of vibration. I want to... |
In textbook electromagnetism we are used to seeing neat, coordinate-free, expressions for the scalar potential from an electric dipole (using Gaussian units)
$$\phi(\mathbf{r}) = \frac{\mathbf{p} \cdot \mathbf{r}}{r^3}$$
and vector potential from a magnetic dipole
$$\mathbf{A}(\mathbf{r}) = \frac{\mathbf{\mu} \times \m... |
When reactants undergo exothermic reactions, e.g. combustion of hydrocarbons, energy is conserved when some energy in the chemical bonds of the reactants is transformed into kinetic energy of the products.
Then some of the products would have gained an increase in kinetic energy (i.e. its velocity has changed) meaning ... |
I have a doubt about the definition of Bravais lattice for periodic materials.
Precisely, here it is defined as:
a discrete set of vectors closed under vector addition and subtraction
If I look at the following picture, I understand it: if we evaluate the vectorial sum/subtraction of a1 and a2, we get another points ... |
It is always said (and this is even how physicists motivate some theories instead of others) that the physics is preserved (by some transformation) whenever the equations of motion are left unchanged by some transformation and/or symmetry.
This yet seems completely false. In General relativity for example, because Eins... |
equipment required: dynamo or an alternator or generator (all should be small about 17V).
As due to COVID19 i am unable to buy any of the mentioned equipment as the online shopping service providers are unable to deliver at my place. So i thought instead of wasting my time i could go some repairing shops to search for ... |
Take, for example, a futuristic-looking square "lamp" (effectively a metal cube that emits light).
Overall we assume the lamp can be made to have a mass of around ~20 grams as this is roughly equivalent to a common frog, one of which had once been levitated using diamagnetism.
Placed at the bottom of the inside of the ... |
A rope of mass per unit length $\mu$ has a static breaking strength $F$. What is the largest possible $F$ that does not violate the weak energy condition, i.e. $T^{00}$ should be positive to all observers?
I found a solution where $T^{0'0'}$ is given by
$$T^{0'0'}=T^{\mu\nu}U_\mu U_\nu$$
where $U^\mu$ is the four veloc... |
My understanding is that Yang's double-slit experiment only works with monochromatic light.
Does it mean that polychromatic light behaves differently then monochromatic light? Or are we simply limited in our measurement tools to detect the same effect with polychromatic light?
Assuming there are different levels of po... |
For example how are stress, strain and shear tensors described invariantly, without any coordinates, purely in a geometric manner?
A formulation that avoids indices coordinates and matrices, even in practical calculations.
|
I encounter a question regarding the derivation of the normalization of 1 Particle states in Weinbergs book (Formula 2.5.14).
Similar questions were asked in A question on page 65 of Weinberg's QFT volume 1 and Inner product of standard-momentum one-particle states in Weinberg but I didn't see my questioned answered.
... |
This is a long question and the main points are emphasised in bold.
Consider a non-Abelian SU(N) gauge theory. $t_a $ is an Hermitian
generators of SU(N) so that $$U = e^{i\alpha^a(x)t^a} \tag{1}$$ is an element of
SU(N), where $\alpha^a(x)$ are real. $\phi$ is a scalar field transforming
in the fundamental:
$$\tag{2} ... |
Laser light shows the unique property of coherence. This is due to the stimulated emission process of photons. But why is it that stimulated emission leads to coherence?
|
I know that in $\mathcal{N}=4$ SYM there is superconformal symmetry $su(2,2|4)$.
Does this exhaust all symmetries of this theory?
Or there are some more unobvious symmetries?
Maybe AdS/CFT predict such symmetries?
|
I'm confused about two things : the illustration and the "vector" in magnetic field .
I didn't understand why the potential created by magnetic field got vector . I know about Helmholtz theorem , but it's unclear for me since we know that potential is scalar unit but here it's vector .
Also I don't get why there is no ... |
{$\vec E$ - Electric Field Vector ; $x^2$ is $x$ raised to the power $2$}
When finding the Potential Difference between two points in a non uniform electric field, the equation of $\vec E $ given in the question is something like this
$$\vec E = 2xydx + (x^2)dy$$
Upon integrating (to find the potential difference) the... |
The $LC$ circuit I'm considering contains a capacitor, an inductor and an electrical resistance. There is no battery: intially the capacitor has a charge $Q$ and the electric current in the circuit is zero. I know the equation that describes this circuit is $$q'' + \frac{R}{L}q' + \omega^{2} q = 0$$ with $\omega = \fr... |
While one are using Hamilton Principle on density Lagrangian, he may find this
$$\delta (\partial_{\mu} \phi_{i}) = \partial_{\mu} (\delta \phi_{i})$$
Why this statement are true?
|
This is similar to this question: Is the converse of Noether's first theorem true: Every conservation law has a symmetry?. However, the answer given there is very technical and general. I am only interested in the specific case of energy conservation (mostly because dark energy seems to break energy conservation / time... |
What I understand...
A tomographically complete set of operators is a set of operators such that measuring the probability distributions of an unknown quantum state over the spectrum of each of these operators allows you to write down the pre-measurement quantum state (of course, one needs infinitely many copies of the... |
So we know that the gravitational potential energy between two objects is, $$-GMm/r.$$
How would we derive this? I am curious behind the intuition of this formula.
|
I'm just wondering if there is a way to physically measure the covariant and contravariant components of a vector without prior knowledge of the metric.
Suppose I have a speedometer of some sort to measure the speed relative to me, of some faraway slowly moving and non interacting dust cloud in some area with dark matt... |
I was learning about surface tension, and came across the curious concept of surface energy. My physics textbook defines it as the potential energy of molecules which helps them remain on the surface (and thus not go inside).
However I have 2 questions about the concept of surface energy. Firstly, why would the water m... |
QED in 1+1 dimensions with a massive fermion, called the massive Schwinger model, has a phase transition at $\theta=\pi$ for some finite critical mass $m_c$. Equivalently, one can say that the Schwinger model has a phase transition at $\theta=0$ and $-m_c$ because a shift of $m\to -m$ corresponds to a shift of $\theta\... |
From this article Fine Tuning Problem (Perez, Weizmann Institute of Science, Lecture Note) in section C, the hierarchy problem arises from the fact that there are quadratically divergent loop contribu18tions to the Higgs mass. The most significant of these divergences come from three sources. They are the top quark, t... |
It is common to refer to fixed points of the renormalization group as scale invariant theories. This statement can be formulated as $$ \beta(\mu) \Big |_{\mu^*} = 0 \; \; \Longrightarrow \; \; T^{\mu}_{\mu} = 0 .$$
However, I never saw a proof of this fact and I do not think it is trivial. How can I approach it?
|
I have doubt in the statement is there any link between surface charge and object enclosed within the shell.
I think object in enclosed shell can have any charge +ve or -ve .
Or it is due to the fact that if +ve charge is distributed over the sphere then electric field inside the shell is zero
|
At page 44 of Modern Quantum Mechanics by Sakurai it's stated that given the following formula for the translation operator ($T$):
$$T(d\vec{x}')=1-i\vec{K} \cdot d\vec{x}'$$
(where for some unknown reason $1$ represents the identity matrix $\mathbb{I}$) we can identify $\vec{K}$ with the momentum operator $\vec{p}$. I... |
Suppose I have an electric car with a battery capacity of N kWh, how many kWh of power do I need to recharge it? It can't be a precise match of N - some must be lost through heat, powering the charging unit, etc.
Is it a significant percentage or is it negligible enough to be able to use the capacity of the battery as ... |
What happens when two ergospheres of oppositely spinning black holes of the same mass, axis of rotation, and speed of rotation approach each other?
What would happen to the black holes in question?
|
I am consideringflow between a rigid cylinder parallel to a rigid horizontal stationary surface. Assuming that we can apply the lubrication limit (so that the cylinder is very close to the surface) I cannot understand why the net fluid force acting on the surface has no component perpendicular to it.
Could someone plea... |
What is a lukewarm black hole?
They supposedly have something to do with hawking radiation.
I would like an explanation of their properties.
|
As I know, when a magnet is cut perpendicular to its axis of magnetization the cut ends attract to each other as they become opposite poles.
But I recently watched a video that said it only happens in artificial magnets and if you cut a natural magnet perpendicular to its axis of magnetization a pole reversal occurs an... |
If we replace the mass by a point mass, equate the forces in the diagram and do small angle approximation, we would reach at regular pendulum angular frequency formula
i.e:
$F=ma$
$-mg\sin \theta= ma$
$ -mg \frac{x}{L} = ma$
comparing with harmonic oscillator, we get
$ \omega=\sqrt{\frac{g}{l}}$
But the correct answer... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.