# Tag Info

4

They do form, but don’t last long. Delta baryons can have three up quarks (for the $\Delta^{++}$) or three down quarks (for the $\Delta^-$). These baryons are unstable and last only a few trillionths of a trillionth of a second.

4

Typically, the single variable surrounded by angled brackets denotes some sort of mean value. In this case, I suspect it might be with respect to time: $$\langle i\rangle\triangleq\frac{1}{T}\int_0^Ti(\tau)\,\mathrm{d}\tau$$ where $T$ is the period. See the Wikipedia entry on such brackets for more. Another alternative, though not likely in this case, is ...

3

The short answer it is highly unlikely it will cause lethal electric shock. Here is the reason why. Lethal electric shock requires current of sufficient magnitude and duration to flow through your heart to cause ventricular fibrillation or cardiac arrest. This means there has to be two contacts on the body with the source of current in order to have a ...

2

Because of the huge number of protons and electrons present in a handy-sized chunk of matter (like, for example, a baseball), if there were even a very tiny difference in the magnitude of the charge between an electron and a proton in a single atom, that difference would give rise to macroscopic effects that could easily be measured. Those effects do not ...

1

the measurement tool is called an electrostatic voltmeter. I do not know if any exist that you could slip into and out of your pocket to make field measurements though.

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Let me add something to the Kyle Kanos's answer and the belonging discussion: In general the angle brackets denote an expectation value of a random variable $x(t)$. You can determine the expectation value of this variable by either averaging over time or by an average over an ensemble. The question if these two quantities are the same is related to ...

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There is absolutely no difference between charge and mass. Just as Earth exerts an attractive force on each object, proportional to that object's mass (and Earth mass, too), irrespective of the number or masses of the objects around, so the force exerted by a proton on each electron is independent on the presence of more electrons. However, electrons exert a ...

1

Classically, in SI units, for two electrons each with charge -e separated by distance $r$ magnitude of electrical repulsion is given by $$F_e=\frac{1}{4\pi\epsilon_0}\frac{e^2}{r^2}$$ where symbols have their usual meaning. magnetic interaction: depends on the magnetic moments of the two electrons(which stem from its spin angular momentum and charge) ...

1

Cute question. The magnetic field of a dipole is $$B=\frac{k\mu\beta}{c^2}r^{-3},$$ where the unitless factor $\beta$ depends on the direction. Here $\mu$ is the dipole moment, $k$ is the Coulomb constant, $c$ is the speed of light, and $r$ is the distance. Approximating the $g$ factor of the electron as 2, we have $$\mu=\hbar\frac{e}{m},$$ where $e$ is ...

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