# Electromagnetism static charge and forces

• The black vegetable
In summary, the conversation revolves around justifying the inequality |F(a)| > |F(b)| > |F(c)|. The speaker suggests that special relativity may explain why |F(b)| > |F(c)|, but is unable to justify why |F(a)| > |F(b)|. They mention that they are new to electromagnetism and are trying to understand the concept.

#### The black vegetable

Hi
Everyone, I'm trying to justify to myself why

|F(a)| > |F(b)| > |F(c)|

I think I can see why

|F(b)| > |F(c)|

due to special relativity case c observed from
the charges point of view would observe
the charges closer due to lorentz
contraction. As the charge is invariant would
result in a greater force?

However I can't justify to myself why
|F(a)| > |F(b)|

many thanks

The black vegetable said:
would observe the charges closer due to lorentz contraction.
In which direction is the contraction?

Please ignore my justification, I see now it's wrongIm Just trying to find out why

|F(a)| > |F(b)| > |F(c)|

I know that |F(a)| and |F(c)| have the same
electric force independent of motion and that the weaker force
experienced by |F(c)| is a result magnetic attraction

but can't see why
|F(a)| > |F(b)|

I'm new to electromagnetism

many thanks

## 1. What is electromagnetism?

Electromagnetism is the branch of physics that deals with the study of the interactions between electrically charged particles and electromagnetic fields. It is a fundamental force of nature that is responsible for many everyday phenomena, such as electricity, magnetism, and light.

## 2. How is static charge created?

Static charge is created when electrically charged particles, such as electrons, are transferred from one object to another through friction, contact, or induction. This results in an imbalance of positive and negative charges on the objects, which can cause them to attract or repel each other.

## 3. What is the difference between static electricity and current electricity?

Static electricity refers to the build-up of electric charge on the surface of an object, while current electricity is the flow of electric charge through a conductor. Static electricity is typically seen in situations where there is minimal or no movement of charge, while current electricity is present when there is a continuous flow of charge.

## 4. What is the relationship between electromagnetism and magnetism?

Electromagnetism and magnetism are closely related and are both a result of the interactions between electrically charged particles. Moving electric charges create magnetic fields, and changing magnetic fields can induce electric currents. This relationship is described by Maxwell's equations, which unify electricity and magnetism into a single theory of electromagnetism.

## 5. How do electric charges interact with each other?

Electric charges interact with each other through the electric force, which can be attractive or repulsive depending on the charges involved. Like charges repel each other, while opposite charges attract each other. The strength of the electric force between two charges is directly proportional to the magnitude of the charges and inversely proportional to the square of the distance between them, as described by Coulomb's law.