All Questions
Tagged with electromagnetism forces
88
questions
122
votes
10
answers
17k
views
How can I stand on the ground? EM or/and Pauli?
There is this famous example about the order difference between gravitational force and EM force. All the gravitational force of Earth is just countered by the electromagnetic force between the ...
- 1,321
56
votes
13
answers
23k
views
Is there an intuitive explanation for why Lorentz force is perpendicular to a particle's velocity and the magnetic field?
The Lorentz force on a charged particle is perpendicular to the particle's velocity and the magnetic field it's moving through. This is obvious from the equation:
$$ \mathbf{F} = q\mathbf{v} \times \...
- 677
44
votes
5
answers
20k
views
Can the Lorentz force expression be derived from Maxwell's equations?
The electromagnetic force on a charge $ e $ is
$$ \vec F = e(\vec E + \vec v\times \vec B),$$
the Lorentz force. But, is this a separate assumption added to the full Maxwell's equations? (the ...
- 1,342
16
votes
2
answers
9k
views
If the strong nuclear force is stronger than electrostatic repulsion, why don't nuclei collapse into a point?
Today in class we were discussing the strong nuclear force, and our teacher was explaining about how the strong nuclear force counteracts the repulsion force between protons in a nucleus.
When asked ...
- 183
5
votes
1
answer
4k
views
Two electron beams exert different forces on each other depending on frame of reference?
I am sure there is a simple explanation for my confusion, but I am a little puzzled:
We are dealing with two parallel electron cannons that each produces a straight beam of electrons. They are placed ...
- 53
16
votes
4
answers
18k
views
Are the Maxwell's equations enough to derive the law of Coulomb?
Are the 8 Maxwell's equations enough to derive the formula for the electromagnetic field created by a stationary point charge, which is the same as the law of Coulomb
$$ F~=~k_e \frac{q_1q_2}{r^2}~? ...
- 727
78
votes
4
answers
11k
views
How exactly is a normal force exerted, at the molecular level?
I've been surfing the web for quite a while, finding the answers I would need, but couldn't find a convincing one. First of all I need to remind you that this a very long/continuous question, so ...
user226894
27
votes
4
answers
6k
views
Is the EmDrive, or "Relativity Drive" possible?
In 2006, New Scientist magazine published an article titled Relativity drive: The end of wings and wheels1 [1] about the EmDrive [Wikipedia] which stirred up a fair degree of controversy and some ...
user8616
3
votes
3
answers
3k
views
Protons and Electrons Occupying the Same Space
When it comes to atoms electrons can't fall into the nucleus, which besides the off hand uncertainty explanation, I'm not sure which force prevents them from falling into the nucleus. I thought I ...
user24082
23
votes
1
answer
2k
views
What are the proposed theoretical explanations for the EmDrive?
The EmDrive is a proposed propulsion mechanism for spacecraft in which some form of microwave device provides the propulsion. The consensus from the physics community, including many voices on this ...
5
votes
2
answers
3k
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 ...
- 539
1
vote
4
answers
4k
views
Gravitational force and Electromagnetic force?
I found this interesting note in one of my textbooks,
The enormous strength of the electromagnetic force compared to gravity is evident in our daily life. When we hold a book in our hand, we are ...
- 335
4
votes
4
answers
2k
views
Relativistic electromagnetism and electromagnetic forces on 2 protons
The question I have about it is how we can get the same result of net force acting on the individual protons if we judge the system from 2 different reference frames. One using more of the magnetic ...
- 1,324
16
votes
2
answers
8k
views
Why does electric force depend on the medium?
Comparing the equations for the gravitational force
$$\vec{F}_g=-\frac{Gm_1m_2}{r^2}\ \hat{r}$$
and the electric force
$$\vec{F}_e=\frac{Kq_1q_2}{r^2}\ \hat{r}$$
I noticed that the only major ...
- 1,758
13
votes
9
answers
57k
views
What's the core difference between the electric and magnetic forces?
I require only a simple answer. One sentence is enough... (It's for high school physics)
- 245