# Electrostatic forces and the principle of superposition

• anam89
In summary, the principle of superposition states that the effect of multiple sources of energy (such as charges) is the sum of their individual effects, considered separately.
anam89
1. Explain what is meant by statement that electrostatic forces obey the principle of superposition?
2. what does it mean to say that physical quantityis (a) quantized or (b) conserved.

The prinicple of superposition means that effects from multiple sources (charge, for example) is simply the sum of effects from each source, considered seperately. It holds for linear systems.

A physical quantity is quantized if measured values can only take on discrete values- energies of bound electrons, for example. A conserved quantity is one that does not change over time.

question

when we walk briskly across a carpet, you often experience a sparkon touching a door knob.what causes this?and how might it be prevented?

Homework questions?

Andy Resnick said:
The prinicple of superposition means that effects from multiple sources (charge, for example) is simply the sum of effects from each source, considered seperately. It holds for linear systems.

I wonder what exactly you mean with a linear system here. The force isn't a linear function of the distance to a charge

yes, i mean linear force.

kamerling said:
I wonder what exactly you mean with a linear system here. The force isn't a linear function of the distance to a charge

That's a good point. A system characterized by an operator S{} defined as: S{f} = g, where f is the input is considered linear iff

S{a1f1+a2f2} = S{a1f1}+S{a2f2} = a1 S{f1} + a2 S{f2} = a1g1+a2g2. (the a's are constants)

So, for electrostatic force, S{r} = e1*e2/r^2 or whatever. Now for three charges (or two stationary and 1 test charge) we have to be careful to keep track of which r we mean: r1 is the test-charge 1 distance, r2 the test-charge 2 distance. But if you draw a diagram, you can see that the resultant force on the test charge is equal to the summed forces from each of the 2 fixed charges.

Electrostatics and electrodynamics are *usually* linear systems. Nonlinear materials are those that, for example, have a refractive index that varies with intensity. Or performs frequency mixing.

Stress and strain relationships in continuum mechanics are linear only in the limit of infinitesimal deformations. Fluid mechanics is intrinsically nonlinear.

## 1. What are electrostatic forces?

Electrostatic forces are forces that exist between electrically charged particles. These forces can be attractive or repulsive, depending on the charge of the particles.

## 2. How do electrostatic forces follow the principle of superposition?

The principle of superposition states that the total force on a charged particle is equal to the sum of the forces it experiences from all other charged particles. This means that the net electrostatic force on a particle is the vector sum of all individual electrostatic forces acting on it.

## 3. What is the relationship between distance and electrostatic force?

The electrostatic force between two charged particles is inversely proportional to the square of the distance between them. This means that as the distance between two charged particles increases, the electrostatic force between them decreases.

## 4. How does the magnitude of charge affect the electrostatic force?

The greater the magnitude of charge on a particle, the stronger the electrostatic force it will experience from other charged particles. This is because a larger charge creates a stronger electric field, which in turn exerts a stronger force on other charged particles.

## 5. Can electrostatic forces act through non-conductive materials?

Yes, electrostatic forces can act through non-conductive materials, such as air or plastic. This is because the electric field created by a charged particle can extend through these materials and exert a force on other charged particles, even if they are not in direct contact.

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