All Questions
28
questions
9
votes
1
answer
860
views
Electron in the proximity of a magnetic monopole
I am puzzling about an exercise in the book "Electromagnetic Theory" by Ferraro (p.543).
An electron (mass $m$, charge $-e$) in a monopole magnetic field $\vec{B}\left(\vec{r}\right)=g\frac{\vec{r}}{...
- 393
6
votes
3
answers
1k
views
What would it take to cause lightning to jump between the Moon and the Earth?
This question comes from @Floris' speculation at the end of his excellent answer about what it would take to kill everyone on the Earth with electricity.
Doing all this in 1/10th of a second requires ...
- 4,534
3
votes
2
answers
2k
views
How to find the equation of motion of a particle in an electric and magnetic field? [closed]
I'm trying to solve a homework problem. The statement of the problem says:
"When the negatively charged plate of a parallel plate capacitor is lit up by light of a certain wavelength, electrons are ...
- 207
2
votes
3
answers
205
views
Prove a force driven by a cross product between a vector and its velocity gives a spiral movement parallel to the vector
I was given a problem in a Classical Mechanics course that went somehow like the following:
"Consider a particle of mass $m$ moving under the presence of a force $\vec{F} = k\hat{x}\times\vec{v}$, ...
- 382
2
votes
0
answers
492
views
Motion of a charged particle in a "solid" charged sphere (accounting for radiation)
Consider a particle (point charge) with charge $q$ and mass $m$ that crosses into a uniformly charged sphere (with charge $Q$ and radius $R$). The trajectory of the particle is a diameter of the ...
- 31
1
vote
1
answer
54
views
Why does $\vec v \times \vec B$ change to $\vec a \cdot \vec B$? [closed]
I was doing a question where the solution said this:
$$\vec F = q (\vec v \times \vec B)$$
$$m \vec a= q (\vec v \times \vec B)$$
$$ \therefore \vec a \cdot \vec B = 0 $$
$$(x\hat i + 7 \hat j) \...
- 29
1
vote
1
answer
674
views
Charged particle moving in magnetic field using cylindrical coordinate [closed]
It's knowen that a charged particle take a helix trajectory in a uniform magnetic field $B =B e_z$
I tried to study this problem using cylindrical coordinate and i get that
$$F=q v ×B = m a$$
in ...
- 257
1
vote
2
answers
236
views
Non-relativistic limit of a particle in the uniform electric field
For this problem, the solution is:
$$y=\frac{m}{qE}\gamma\left[\cosh\left(\frac{qEx}{mv\gamma}\right)-1\right]$$
where $\gamma = 1/\sqrt{1-v^2}$. Here something seems to be wrong. I think that for the ...
- 1,669
1
vote
2
answers
423
views
Description of the motion of the COM of a system of charged particles moving in a magnetic field
I recently came across a problem where an electrically neutral particle is at rest in a uniform magnetic field. The particle now splits into two charged particles of equal mass $m$; charge and mass ...
- 2,077
1
vote
2
answers
789
views
Movement of the particle in a magnetic field
This is the numerical question.
A particle having a mass of 0.05 mg carries a charge of $5\times10^{-6}C$. The particle is given an initial horizontal velocity of 5000 m/s, what is the magnitude ...
- 2,565
1
vote
2
answers
50
views
Equation for a rotating loop with one fixed end [closed]
This loop is rotating with angular speed $\omega$ in the counterclockwise direction in a magnetic field. I need to find the differential area element (for the purpose of finding flux). Is it going to ...
- 11
1
vote
2
answers
703
views
How to calculate Centripetal force of a helical movement inside a magnetic field?
I have recently studied about the movement of a particle in a basic electromagnetic field. It circulates perpendicular to the field lines.
And the equation is then, $F= Bqv$
$B$ is the value of the ...
- 189
0
votes
3
answers
492
views
Using Binomial and Taylor Expansions to Demonstrate Harmonic Motion [closed]
I'm doing a physics 2 self-study and I came across this question in my textbook:
A ball of mass m and charge q is constrained to move along the y axis. At the origin is a stationary charge Q. The ...
- 1