Why is Coulombs Constant Written as 1/(4*pi*epsilon0)?

In summary, the Coulomb constant is expressed in the form of 1/(4*pi*epsilon0) because it is a useful way to express the empirical value of ~9 x 10^9 due to the geometry required to understand and describe electric fields. This form allows for a nicer representation in equations, particularly when using Gauss' law and considering spherical symmetry. It also involves the use of pi, which can be cancelled out, making the equations simpler. While there are other complexities involving epsilon, this is the main reason for expressing the Coulomb constant in this form.
  • #1
salmannsu
2
0
q: why we express coulomb constant constant in 1/(4*pi*epsilon0) form rather writing as a constant value 9*10^9 ?
why we do not write the value directly as a gravitational constant

why 1/(4*pi) came with the constant, we can directly write the exact value.

whats the benefit of writing in this complex way..please help. i am looking for your help
 
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  • #2
Because then we have in Maxwell's equations we have the nice form
[tex]\nabla\cdot\vec{E} = \frac{\rho}{\epsilon_0}[/tex]
 
  • #3
That is a cool Answer. but why we do that it is not really clear to me . Because coulombs law was suggested much more earlier that Gauses law and Maxwell equation. So why we changes in coulombs law rather changing Maxwell equation. Is there any significance ?
 
  • #4
salmannsu said:
That is a cool Answer. but why we do that it is not really clear to me . Because coulombs law was suggested much more earlier that Gauses law and Maxwell equation. So why we changes in coulombs law rather changing Maxwell equation. Is there any significance ?

It is a useful way to express the empirical number of ~9 x 10^9 due to the geometry required to understand and describe some simple electric fields. Many electric fields are incredibly complex but those that show spherical symmetry can be described. If one starts using Gauss, and the spherical symmetry required to use Gauss effectively, pi shows up. If you express k in terms of pi you can make the equations look a little nicer because pi pops up and you can cancel it out instead of having to write k with pi in the equation.

Using Gauss and Coulomb for the e-field around a particle it becomes clear that Gauss would require a spherical surface and the total flux would be E.dA and the area of a sphere is 4*pi*r^2. This makes the use of k in terms of 4*pi nice.

Bottom line. It makes things look a little nicer. There are some other complexities involving epsilon, but what I gave you above is what I have gathered after doing problems.
 
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  • #5


Coulomb's constant, also known as the electrostatic constant, is a fundamental constant in physics that represents the strength of the electrostatic force between two charged particles. It is similar to the gravitational constant, which represents the strength of the gravitational force between two masses.

The reason why Coulomb's constant is written as 1/(4*pi*epsilon0) is due to the nature of the electrostatic force. Unlike gravity, which is a long-range force, the electrostatic force between two charged particles decreases rapidly as the distance between them increases. This is because the force is inversely proportional to the square of the distance between the particles.

To account for this rapid decrease in force with distance, the constant 1/(4*pi) is included in the equation. This value is a result of mathematical calculations and does not have a physical significance. It is simply a way to make the equation more convenient to use and understand.

Additionally, epsilon0 (epsilon naught) is the permittivity of free space, which represents the ability of space to allow the electric field to pass through it. It is a fundamental constant that has been experimentally determined and is necessary to accurately represent the electrostatic force.

In summary, writing Coulomb's constant as 1/(4*pi*epsilon0) is a way to account for the rapid decrease in force with distance and to accurately represent the electrostatic force between two charged particles. It is not a complex way of writing the constant, but rather a necessary and accurate representation of the physical phenomenon.
 

1. Why is Coulomb's constant written as 1/(4*pi*epsilon0)?

Coulomb's constant, also known as the electric constant, is written as 1/(4*pi*epsilon0) because it represents the proportionality between the electric force and the distance between two charged particles. The value of this constant is derived from the properties of vacuum, specifically the permittivity of free space (epsilon0) and the geometric relationship of the force between two point charges separated by a distance of 1 meter.

2. What is the significance of the value 4*pi in Coulomb's constant?

The value of 4*pi in Coulomb's constant represents the relationship between a sphere's surface area and its radius. This is important because electric fields, like most force fields, follow an inverse-square law. This means that as the distance between two charged particles increases, the force between them decreases by a factor of 1/r^2, where r is the distance between the particles. The value of 4*pi is necessary to calculate this relationship accurately.

3. Why is Coulomb's constant important in the study of electromagnetism?

Coulomb's constant is important in the study of electromagnetism because it is a fundamental constant that helps us understand the behavior of electric charges. It allows us to calculate the electric force between two charged particles and understand how this force changes with distance. This constant is also used in many important equations, such as Coulomb's law and the calculation of the electric field.

4. How is Coulomb's constant related to other fundamental constants, such as the speed of light and Planck's constant?

Coulomb's constant, along with the other fundamental constants, is a key factor in the study of electromagnetism. It is related to other constants such as the speed of light and Planck's constant through the definition of the fine-structure constant, which represents the strength of the electromagnetic interaction between charged particles. This constant is used to describe the strength of the electromagnetic force in relation to the other three fundamental forces.

5. Is Coulomb's constant the same in all mediums?

No, Coulomb's constant is not the same in all mediums. It is dependent on the permittivity of the medium it is measured in. In a vacuum, it has a value of approximately 8.99 x 10^9 Nm^2/C^2. However, in other mediums, such as air, water, or a dielectric material, the value of this constant will change due to the different permittivity of these materials. This is why it is important to consider the medium when calculating electric forces and fields.

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