All Questions
Tagged with electromagnetism forces
524
questions
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what is in the electrostatic field that makes the word done independent of path taken?
I am trying to understand how is it possible for electric force to behave like this (path independence)?
I am repeatedly failing to get an intuitive meaning behind its (electric field) nature of ...
5
votes
2
answers
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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 ...
- 539
2
votes
0
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117
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Consistency of equation with special relativity?
The following is the equation which, I want to know, if it is valid in relativistic domain. Consider two equal charges moving in same direction with velocity $v$ and charge $q$ at a separation of $d$....
- 3,148
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Two electron beams exert different forces on each other depending on frame of reference?
I am sure there is a simple explanation for my confusion, but I am a little puzzled:
We are dealing with two parallel electron cannons that each produces a straight beam of electrons. They are placed ...
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0
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1k
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Calculation of magnetic force magnitude from a parmenant magnet
I was wondering how strong a magnet should be in order to be able to horizontally attract 0.2 Kg of pure iron at a distance of 0.3 M. Since I know nothing about magnets, I started looking for ...
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10
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Is there any potential associated with magnetism?
Can anybody please tell me if magnetism is a conservative force or if there is a field associated with it? How to reason? One thing I know is that the work done by a magnetic force is equal to $0$.
- 103
2
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1
answer
1k
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Magnetic Force on a Loop and number of turns
Suppose we have a rectangular current-carrying loop with current $i$, then we know that the magnetic force on each side can be found as:
$$F=iL\times B$$
Where $L$ is the vector in the direction of ...
- 36.4k
2
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1
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249
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Falling through the ground [duplicate]
I do not know much about physics but I know that according to Newtons third law of motion when we walk we are pushing the ground down but the ground is pushing us up. What force is making the ground ...
- 21
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3
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Forces as One-Forms and Magnetism
Well, some time ago I've asked here if we should consider representing forces by one-forms. Indeed the idea as, we work with a manifold $M$ and we represent a force by some one-form $F \in \Omega^1(M)$...
- 36.4k
4
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2
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Relativistic Lorentz force law
If we consider the the relativistic Lorentz force law:
$$\frac{d}{dt} (m\gamma \vec{u})=e(\vec{E}+\vec{u} \times \vec{B})$$
How can we deduce:
$$\frac{d}{dt} (m\gamma c^2)=e \vec{E} \cdot \vec{u}$$
...
- 775
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4
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Why in $F = iLB$, $L$ is a vector but $i$ is not?
I learned $F = iLB$ recently. However, I don't understand why $L$ is marked as a vector but $i$ is not.
For a normal rod, how should I define the direction of length vector $L$? And if I reverse the ...
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3
votes
1
answer
2k
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Reason behind cohesive and adhesive force
What is the real cause behind the cohesive and adhesive forces?
- 1,396
4
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1
answer
3k
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Gravity force strength in 1D, 2D, 3D and higher spatial dimensions
Let's say that we want to measure the gravity force in 1D, 2D, 3D and higher spatial dimensions.
Will we get the same force strength in the first 3 dimensions and then it will go up? How about if ...
- 75
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Are the Maxwell's equations enough to derive the law of Coulomb?
Are the 8 Maxwell's equations enough to derive the formula for the electromagnetic field created by a stationary point charge, which is the same as the law of Coulomb
$$ F~=~k_e \frac{q_1q_2}{r^2}~? ...
- 737
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3
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So do I use this Lorentz's law or which law do I use?
I have difficulty understanding exercise 24 in this document:
Two parallel wires I and II that are near each other carry currents i and 3i both in the same direction. Compare the forces that the two ...
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