The inverse stare law.
I don’t understand the formula, but I understand Mr. Bean. +1
If you have two charges q1 and q2, you can get the force between them F by multiplying them with the coulomb constant K (approximately 9 × 10^9) and then dividing that by the distance between them squared r^2.
q1 and q2 cannot be negative. Sometimes you’ll not be given a charge, and instead the problem will tell you that you have a proton or electron, both of them have the same charge (1.6 × 10^-19 C), but electrons have a negative charge.
q1 and q2 can be negative. The force is the same as if they were positive because -1 x -1 = 1
In this case yes, but if q1 was -20μC, q2 was 30μC, and r was 0.5m, then using -20μC as it is would make F equal to -21.6N which is just 21.6N of attraction force between the two charges.
But that if both are negative not one pos one neg like the previous commenter gave in their examples, so the true formula has an absolute value in the numerator: |q1Xq2|
edit: fix similarities typo
Awesome to see the similarities between: Newtonian Mechanics and Quantum mechanics
Coulomb’s law was essential to the development of the theory of electromagnetism and maybe even its starting point, as it allowed meaningful discussions of the amount of electric charge in a particle.
Here, ke is a constant, q1 and q2 are the quantit>ies of each charge, and the scalar r is the distance between the charges.
Being an inverse-square law, the law is similar to Isaac Newton’s inverse-square law of universal gravitation, but gravitational forces always make things attract, while electrostatic forces make charges attract or repel. Also, gravitational forces are much weaker than electrostatic forces. Coulomb’s law can be used to derive Gauss’s law, and vice versa. In the case of a single point charge at rest, the two laws are equivalent, expressing the same physical law in different ways. The law has been tested extensively, and observations have upheld the law on the scale from 10−16 m to 108 m.
They’re different things. The OP means electromagnetism, Coulomb’s law has nothing to do with quantum mechanics, it’s classical physics.
Coulomb had the last laugh though because Newton’s theory has been superseded by relativity.
If there’s anyone who can, please let me know if the similarities between these two formulas imply a relationship between gravity and electrical attraction or hint at a unified theory, or if it’s just a coincidence or a consequence of something else.
The relation between them is that they’re both forces that scale with the inverse square of the distance between the objects. Any force that scales with the inverse square of distance has pretty much the same general form.
Another similarity is that both are incomplete, first approximations that describe their respective forces. The more complete versions are Maxwell’s laws for electromagnetism and General Relativity for gravity.
There’s some relation in that they both act on fields, but the things that affect those fields are very different (higgs bosons and electrons respectively) and the relationship between all that for an ‘unified theory’ is a topic of much research. IANAP though (not a physicist)
Electromagnetism and gravity are both mediated by massless bosons; photons and gravitons respectively. This is why both forces follow the inverse square law.
I don’t think there’s any evidence for gravitons yet, and gravity hasn’t been quantized. I’d say it’s this similarity that’s the best argument of quantum gravity, not the other way around.
Fair. The masslessness of the bosons that should mediate gravity, along with them being spin-2, can however be deduced from the properties of gravitational waves.
There is one thing particularly interesting, and that is that the inverse square laws appears again. It appears in the electrical laws for instance.
That is electricity also exerts forces inverse to the square of distance with charges. One thinks perhaps inverse square distance has some deep significance, maybe gravity and electricity are different aspects of the same thing
…
Today our theory of physics, laws of physics are a multitude of different parts and pieces that don’t fit together very well. We don’t understand the one in terms of the other. We don’t have one structure that it’s all deduced we have several pieces that don’t quite fit yet.
And that’s the reason in these lectures instead of telling you what the law of physics is I talk about the things that’s common in the various laws because we don’t understand the connection between them.
But what’s very strange is that there is certain things that’s the same in both
Richard Feynman and 45:48 https://youtu.be/-kFOXP026eE?si=hAIvDhWVGxMOvEi1
Here is an alternative Piped link(s):
https://piped.video/-kFOXP026eE?si=hAIvDhWVGxMOvEi1
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
It’s really simple, they are both radial fields with a 1/r potential, thus a 1/r² force. Newtonian gravity is just a weak field approximation of general relativity, where you have very different equations, for example Einsteins field equations… One electric charge creates an electric field, and another charge will interact with it, but the motion itself still depends on the mass of the second charge. Matter instead curves spacetime itself, and the curved spacetime tells matter how to move. Source: MS in physics.
Doubtful but interesting thinking. It’s actually a rather simple equation that explains how two equally weighted forces affect one another over distance. The numerator expresses that both forces carry equal weight in the interaction (if they are both the same kind of force, eg gravity or electromagnetism, this makes sense) and they are constructive interactions (both add to the intensity of the interaction) hence multiplying one by the other. The denominator just indicates that the distance between the two things exponentially degrades the force at a power of 2, since the force is spreading out in 2 dimensions (imagine a cone starting at one point and extending to the second, so that when you reach the second point the force is spread across the cross section of that cone, but the only part of the force affecting that second point is the part that touches it).
