4
votes
2answers
133 views

What is potential energy truly?

I have a problematic question for which I have been unable to attain a satisfactory answer. What is potential energy truly? - I have read about how potential energy can be seen as the "highering" ...
2
votes
0answers
151 views

What is the minimum physical distance between two electrons?

If electrons repel, then it seems to me that energy is required to decrease the distance between two electrons. Since energy and mass are equivalent, adding energy to a system also adds some mass. ...
2
votes
3answers
158 views

Is there energy stored when iron is magnetized?

When a piece of iron is magnetized, and the domains are aligned, Is there energy stored? If so, how much energy is stored? If there is an attraction between that same iron and the source of the ...
1
vote
2answers
197 views

Deriving the Lorentz force from velocity dependent potential

We can achieve a simplified version of the Lorentz force by $$F=q\bigg[-\nabla(\phi-\mathbf{A}\cdot\mathbf{v})-\frac{d\mathbf{A}}{dt}\bigg],$$ where $\mathbf{A}$ is the magnetic vector potential and ...
0
votes
0answers
89 views

Potential energy: Electric field two spherical charges

I want to determine the potential energy of two equally charged spherical charges by using the equation: $V_{pot}= \int_V \frac{1}{2} \epsilon_0 E^2 dV$ and therefore I was wondering what I has to ...
0
votes
1answer
734 views

Potential energy of the dipole-dipole interaction for two parallel dipole moments

I am looking for an equation that gives me the potential energy of the interaction between two parallel dipoles.
2
votes
2answers
180 views

Coincidence, purposeful definition, or something else in formulas for energy

In the small amount of physics that I have learned thus far, there seems to be a (possibly superficial pattern) that I have been wondering about. The formula for the kinetic energy of a moving ...
0
votes
1answer
48 views

About electrostatic potential energy

I consider an electron (charge $-e$) in $x=0$ and a constant electric field $E(x) \equiv E $. If the electron has initial velocity $v_0$ with the same direction of $E$, then its potential energy is $$ ...
-2
votes
2answers
522 views

Electric potential energy and speed

If we have electric field and we put electron there , the electron will move in the opposite direction as the electric field. My question is electron in that direction will speed up or slows down ? ...
2
votes
2answers
1k views

Higher To Lower Electric Potential

The question I am working on is: "An electron moving parallel to the x axis has an initial speed of $4.65 \cdot 10^6~m/s$ at the origin. Its speed is reduced to $1.27 \cdot 10^5 ~m/s$ at the point ...
1
vote
1answer
85 views

Is more energy required to magnetize based on its distance to other objects?

I have had this question since I was in college physics, but never could figure out how to express it. Well, now I think I have it. Let's imagine two scenarios A and B. Both scenarios start with two ...
1
vote
3answers
947 views

Electricity & Magnetism - Is an electric field infinite?

The inverse square law for an electric field is: $$ E = \frac{Q}{4\pi\varepsilon_{0}r^2} $$ Here: $$\frac{Q}{\varepsilon_{0}}$$ is the source strength of the charge. It is the point charge divided ...
7
votes
5answers
1k views

Direction of rotation of proton in magnetic field--opposite to a dipole

Chatroom created by @pcr for discussing this: http://chat.stackexchange.com/rooms/2824/direction-of-rotation-of-proton-in-magnetic-field Here's a small paradoxical question I was asked a long ...
2
votes
1answer
189 views

Asynchronous generator run in vacuum chamber

what will be happen if we put asynchronous generator in vacuum chamber & run it above its synchronous speed. After reaching its over synchronous speed we will cut off electrical supply. Can it run ...
0
votes
1answer
190 views

Violation of conservation of energy and potential energy between objects

I would like to clarify my question. I have numbered them to be independent questions For any conservative fields, $\vec{F} = -\nabla U$. Which means the restoring force is opposite to the ...
0
votes
3answers
220 views

What is the physical reason a $+5V$ equipotential coutour cannot intersect a $-5V$ equipotential coutour?

Now I've been told that equipotential contours with different values can never intersect. That is, if one level is 5V and one is -5V, they can't intersect. This make sense to me mathematically (one ...
2
votes
3answers
937 views

Potential energy of a charged ring

Consider a ring of radius $R$, and charge density $\rho$. What will be the potential energy of the ring in its self field? The best I can do: $$dq = \rho R \cdot \, d \alpha $$ $$E_p = 2 \pi R \cdot ...