All Questions
7
questions
3
votes
4
answers
393
views
How strong would the electromagnetic field of the earth and the planets would have to be, in order to mimic the effects of gravity? [closed]
How strong would the combined forces of electromagnetism on the earth and planets need to be, to mimic, and therefore, replace gravity?
- 43
7
votes
4
answers
4k
views
Can Newton’s law of gravitation be derived from Coulomb’s law? [duplicate]
I’m casually learning physics and have noticed that Newton’s law of gravitation and the electrostatic force formulas look similar. I’ve asked this question before but would really appreciate another ...
- 257
8
votes
2
answers
583
views
Calculating the potential on a surface from the potential on another surface
The question is short: If a charge (or mass) distribution $\rho$ is enclosed by surface $S_1$, I can calculate the electrostatic (or gravitational) potential on that surface by integrating $\rho(r') \ ...
- 6,273
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
-1
votes
1
answer
3k
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 ...
- 209
21
votes
2
answers
3k
views
Is Newton's universal gravitational constant the inverse of permittivity of mass in vacuum?
Is it possible to consider Newton's universal gravitational constant, $G$, as inverse of vacuum permittivity of mass?
$$\epsilon_m=\frac {1}{4\pi G}$$
if so, then vacuum permeability of mass will be:...
user26425
9
votes
3
answers
1k
views
Negative Mass and gravitation
Since Newtonian gravity is analogous to electrostatics shouldn't there be something called negative mass? Also, a moving charge generates electric field, but why doesn't a moving mass generate some ...
- 559