A fundamental and empirical law quantifying the electrostatic force between two charges.

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The maximum distance for which Coulomb's law has been verified?

We know that Coulomb's law, $F_{12} = \frac{kq_1q_2}{r^2}$, was experimentally verified for small distances by Coulomb himself at the and of the XVIII century. The question is what is the maximum ...
2
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0answers
39 views

How much time would it take for a positively charged particle to get to an infinite, negatively charged wall?

There is a negatively charged wall($q$), which has equal charge density. There is a positively charged particle($Q$) with a mass of $m$, the distance between them is $d$. How much time would it take ...
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1answer
53 views

Photon as a mediator of electric field

How can a photon (which has momentum) from one electrically charged particle to an oppositely charged particle cause these particles to be pulled toward each other - or how can a magnetic field cause ...
4
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1answer
272 views

Why can protons collide?

Electromagnetic repulsion is inversely related to the square of the distance between both objects. Shouldn't this mean that the integral of the force between two protons is infinite if the distance ...
0
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1answer
57 views

How to understand photons in terms of EM force carrier? [duplicate]

Say, there are 2 stationary electrons placed at a distance. The result of observation would be both flying apart with the same speed and the opposite direction, which would obey laws of conservation ...
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0answers
76 views

Coulomb potential of a periodic crystal in reciprocal space

Usually the Coulomb potential (electron-electron interaction) can be Fourier transformed (aside from prefactors) like that: $$ \frac{1}{|\vec r_1 -\vec r_2|} = \int \frac{\text d ^3 k}{(2\pi)^3} \frac{...
0
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2answers
80 views

Is antimatter attracted to matter by its opposite electric charge?

As it is said by many physicists that antimatter is just opposite of matter; it has opposite charge of matter, then is there is any possibility that antimatter is attracted to matter? For example - ...
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1answer
89 views

Why don't we consider the electromagnetic field in the equations of Bohr's theory of atoms? [duplicate]

hi,i know these, my mean that the magnitude magnetic field B formule that i find here my question is that we consider Coulomb force in Bohr's theory but don't consider the electromagnetic field? An ...
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3answers
164 views

Does the force between two point charges change when inertial reference frame changes?

The two point charges are as below: Then the Coulomb force between them is: $$F_1=\frac{q^2}{4\pi\epsilon_0 r^2}$$ When the inertial reference frame moves left at $v$(or the point charges move ...
0
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1answer
44 views

Solve the inverse function of the solution to a varying acceleration problem ODE

Suppose there are two positive charges $A$ and $B$, both with equal mass $m$ and the same charge quantity $q$. The initial distance between $AB$ is $R$; and the initial velocity of $B$ relatively to $...
0
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1answer
440 views

Force between two charges when the dielectric constant of the material varies?

If two point charges $q_{1}$ and $q_{2}$ are seperated by a distance $l$ apart, and the space between them is filled with a variable dielectric constant. Near $q_{1}$, the dielectric constant is $K_{1}...
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1answer
76 views

Will Coulomb law work if both the charges are moving with same speed and same direction?

I read it on wikipidia that Coulomb law will work if both the charges are at rest relatively. Will there be an effect of magnetic field also?
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2answers
35 views

Finding Charge given Electric Field

This question came up in a competition, and I didn't know how to solve it. ABCD is a rectangle with width $2d$ and height $d$. At point D, there is a charge with magnitude $q_1$ At point B, there ...
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0answers
29 views

Does a Description with Photons as Force Carriers Apply for Non-Radiative Systems?

What is the full quantum mechanical description of the statement from classical electromagnetism "the electric field of a uniformly charged infinite flat plane is constant"? By "full" I mean that I'm ...
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1answer
468 views

What is the difference between an electric field and gravitational field? [duplicate]

Since the electrostatic field and the Newtonian gravitational field share a similar form: proportional to $$ \frac{1}{r^2} $$ Is there any qualitative difference between motions under the ...
5
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2answers
118 views

Is Quantum Coulomb still singular?

A single free charge (e.g. electron) $q$ fixed at the coordinate origin has the well-known Coulomb/electric potential $$\phi(\vec r) = \frac q{4\pi\epsilon_0}\frac 1r \tag{A}$$ where $r=|\vec r|$ of ...
0
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1answer
61 views

Electrons in graphene will behave as in 2D space?

Will electrons in graphene behave as in pure 2D space, that is they interact with eachother by a Coulomb potential ~ $\ln r$ instead of $1/r$? I think many force lines will "leak" out of graphene ...
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1answer
60 views

An Electron Chasing Another

An electron is held in place in deep space. Another electron approaches with speed $v_0$. When the approaching electron is a distance $r_0$ away from the first electron, the first is set free. The ...
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2answers
25 views

Nucleus validation [duplicate]

Inside the nucleus of an atom is the Coulomb's law valid? I mean that between proton, neutron and other elementary particles, i.e., meson etc. What will be the limit or validity of charges between ...
2
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1answer
119 views

Coulomb's law with an $r^3$, not $r^2$, in the denominator [duplicate]

I am reading an older physics book that my professor gave me. It is going over Coulomb's law and Gauss' theorem. However, the book gives both equations with an $r^3$, not $r^2$, in the denominator. ...
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3answers
137 views

Is the electric field at a single point inside a charged sphere zero?

Many physics textbooks say, Gauss' law shows that the electric field inside a sphere with uniform charge distribution on the surface equals zero. What I want to know is, do they mean total, i....
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1answer
188 views

Force acting on a charge between parallel plates

When a charge (say positive) is placed between an upper positively charged plate and a negatively charged plate, it should experience a repulsive force from the top plate and an attractive force to ...
11
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4answers
1k views

Do electrostatic fields really obey “action at a distance”?

In an electromagnetic theory class, my professor introduced the concept of "action at a distance in physics". He said that: If two charges are at some very large distance, and if any one of the ...
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0answers
59 views

Importance sampling for Coulomb potential

The integral I have to solve is: $$I=\int\int d \mathbf{r}d \mathbf{r}' \frac{\Phi(\mathbf{r})\Phi(\mathbf{r}')}{|\mathbf{r}-\mathbf{r}'|}$$ It is a six-dimensional integral which I am going to ...
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1answer
50 views

Coulomb collision

I was reading an article by N. Bohr and came upon the following problem (the following wording is actually taken from a book by Thompson - Conduction of Electricity Through Gases): Let $M_1, M_2$ ...
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1answer
74 views

What is colour-Coulomb interaction?

In several publications (e.g. http://arxiv.org/abs/1506.06864) a "colour Coulomb interaction" between quarks was mentioned. What kind of interaction is that, is it electromagnetic or strong?
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45 views

Collision between electrons & nucleus [duplicate]

I am new with physics and I have a confusion that since electron and nucleus has opposite charges then why they do not collide with each other inside an atom?
0
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1answer
282 views

Interaction Energy vs Force

I'm having a hard time determining the relationship/differences between interaction energy and forces. Say we have a system of two charged particles. Each particle will exert a force on each other (...
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1answer
81 views

What does multiplying of charges means?

Today I learned Coulomb's law, and I didn't get what does this multiplication $q_1 * q_2$ gives? I want to understand this visually.
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1answer
118 views

What is the purpose of defining an electric field, and how to apply it?

So, I've been reading an introductory book to physics. I've gotten to the point where I understand Coulomb's law, and now the book is introducing electric fields. I'm having a hard time ...
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0answers
67 views

Sphere of electric charge revisited

I am thinking about a sphere of homogeneous charge distribution (see Electric field due to a solid sphere of charge, for example). Here we use a Gaussian surface (blue area) to find the electric ...
0
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1answer
2k views

Application of Coulomb's Law

I've just finished reading a section in a book on Coulomb's Law. I'm trying to practice the math a bit and came up with the following: Suppose you have two charges, -5uC ($q_1$) and 7nC ($q_2$). ...
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2answers
134 views

An infinite value for an electric field?

Consider a system of point charges. To calculate the value of an electric field at a point, we consider the contribution of the electric field from all the charges at that point. Consider the ...
0
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1answer
1k views

Deriving Coulomb's law from quantum electrodynamics [duplicate]

Is it possible to derive the Coulomb's law using the principles of quantum electrodynamics? How?
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1answer
37 views

where does the term half in the formula of electrostatic potential energy comes from?(system of point charges)

Electrostatic potential energy stored in a system of point charges (from wikipedia) The electrostatic potential energy $U_E$ stored in a system of N charges q1, q2, ..., qN at positions r1, r2, ...,...
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2answers
88 views

a question about work needed to move a charge towards another one [duplicate]

Consider two charges $q_1>0$ & $q_2>0$ separated by a distance $d_1$, and we want to move charge $q_2$ to a distance $d_2$ from $d_1$ where $d_1-d_2>0$. I need to calculate the work ...
0
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2answers
88 views

simple force question

So given this diagram, I was supposed to find the magnitude and direction of the net force on the -10nC charge on the bottom right corner. I found the magnitude by myself using Coulomb's law for the ...
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2answers
58 views

What is the intuitive meaning behind Coulomb's constant $k_e$?

What is the intuitive meaning behind Coulomb's constant $k_e$? If the force of an electric field can be calculated by $$F=k_eqQ/d^2$$ If I could guess I would say $k_e$ is the acceleration but I am ...
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1answer
38 views

Understanding the differences and applications of some electrical equations

In preparing for the AP Physics 2 test tomorrow, (the first year this test is being offered, so this material is not easily searchable), I've been doing some reviewing of the equation sheet and trying ...
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1answer
427 views

dipole field on axis twice the field on perpendicular bisector

Why is the dipole field on axis twice the field on perpendicular bisector? For the perpendicular bisector: Lets assume -q is right from of the origin and +q is left from the origin, both a distance a ...
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1answer
2k views

Graph of electric potential

In my AP physics guide the graph for electric potential (for a radial field, i.e. point charge) and gravitational potential (for radial field, i.e. point mass) slightly differ from each other and I ...
2
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1answer
318 views

Is there a fundamental relationship between Coulomb's law and Newton's Law of Gravitation? [duplicate]

It seems like the two equations are identical indicates that there is something more going on that unites them both, maybe in a cool way or something. Why are these two laws so similar?
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1answer
121 views

Why do inverse square forces not rise asymptotically for $r\to 0$?

An example of an inverse square force is the gravitational force: $$ F = \dfrac{G m_1 m_2}{r^2}$$ For large bodies I can understand why the force does not rise asymptotically as you get closer. For ...
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2answers
169 views

Induction in Electrostatics

While solving some problems on electrostatics, I came across this question : Two balls carrying charges of +3 $\mu C$ and -3$\mu C$ attract each other with a force $F$. If a charge of +3$\mu C$ is ...
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3answers
117 views

Lower limit value of electric force [closed]

What is the lower limit value to the electric force between two charges separated by a fixed distance?
0
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0answers
35 views

Infinite force between two point charges as $r$ approaches 0 [duplicate]

According to coulombs law the Force experienced by two point charges increases with the inverse square of their separation. This would imply that at distances approaching 0, the Force approaches ...
1
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2answers
190 views

Force when distance between charge is zero

According to coulomb law $$ F = \frac{q_1q_2}{r^2} $$ I want to know what happens to force when $r=0$. If $F \to \infty$ then the charges can't be separated! But if an unlike charge of higher ...
2
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1answer
69 views

Special relativity, electromagnetic fields, charge and Q

Is it true, were Coulomb's constant k to be several orders of magnitude smaller, that there would be no (or increasingly negligible) magnetic fields generated by moving charges? The reason being the ...
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2answers
2k views

Direction of electric field lines and electrostatic force

Direction of electric field and electrostatic force should be same by the equation $$\vec{F} = \frac{k q q_0}{r^2}$$ Electric Field $$\vec{E} = \frac{k q}{r^2}$$ Let us suppose that there is a ...
2
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1answer
80 views

Why does the medium affect the Coulomb's constant but not the gravitational constant?

Why does the medium affect the Coulomb's constant but not the gravitational constant? My friend said maybe the particles of the medium affect the electric field. But the net charge in the medium is 0 ...