Alpha001
  • Member for 6 years, 2 months
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What does electrical potential at a point mean?
3 votes

You can think of it in such a way. Let $\phi(x)$ be the potential function of an electric field $\vec{E}$ with boundary conditions $\lim\limits_{x\to \infty} \phi(x) = 0$. For the potential we obtain ...

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Is force the current of momentum?
3 votes

The momentum is given by: $$ p = \int_{t_0}^{t_1} dt F(t) $$ The change of momentum $\dot{p}(t)$ is therefore related to the force $F(t)$. If you want you can say that in some sense your statement ...

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Time evolution of operators, derivation
Accepted answer
3 votes

It is a change of view. In the Schrödinger picture your operator is not time dependet (or only explicitly time dependent) but your states evolve with time. On the other side in the Heisenberg picture ...

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Show that the symmetry properties of a tensor are invariant
2 votes

First at all we have to definie under wich transformation the tensors should be invariant. I guess you have some Lorentz transformations in mind. Now we look at the transformation of the tensor ...

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Missing identity element in the Clifford relation
1 votes

Let's try to summarize the characteristics of the $\gamma$-matrices and the metric tensor for flat Minkowski space. First our $\eta^{\mu\nu}$ can be represented by the matrix $$\eta^{\mu\nu} = \...

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How do we realise the wave for an electron orbiting a nucleus in its first orbit as per bohr model?
1 votes

Maybe the term "orbiting" causes some problems. The electron is not moving around the nucleus as bohr assumed (he had no solution according to the problem that an electron on a circular orbit should ...

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Hooke's law, finding spring constant
1 votes

By newton's law you will find for the force of the pendulum without friction and gravity: $$m\ddot{x} = -kx $$ For this you get the solution: $x(t) = A \cdot sin(\omega \cdot t)$. Where $\omega = \...

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Are there any theorems that support the commutation relations in QFT?
1 votes

Indeed we have to implement the CCR or CAR as an axiom to QM/QFT. But if you like to think about it in terms of an action principle look at Schwinger's quantum action principle. From this axiom you ...

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Are all 'substances' made of atoms?
1 votes

There exists something called fermi or bose gas which consits of fermions or bosons. In some sense you can say that this is like a substance. The question is does it exists in the universe? The ...

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forces due to change in mass
0 votes

Assume a body with mass $m+M$ and velocity $\vec{v}_0$ its momentum is given by $\vec{p}_0 = (m+M)\vec{v}_0$: If the body losses mass $m$ (assuming instantanously) and the mass $m$ moves with $\vec{...

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