Coulomb's Law

From Wikiversity

Please help develop this page

This page was created, but so far, little content has been added. Everyone is invited to help expand and create educational content for Wikiversity. If you need help learning how to add content, see the editing tutorial and the MediaWiki syntax reference.

To help you get started with content, we have automatically added references below to other Wikimedia Foundation projects. This will help you find materials such as information, media and quotations on which to base the development of "Coulomb's Law" as an educational resource. However, please do not simply copy-and-paste large chunks from other projects. You can also use the links in the blue box to help you classify this page by subject, educational level and resource type.

Run a search on Coulomb's Law at Wikipedia.

Search Wikimedia Commons for images, sounds and other media related to: Coulomb's Law

Search for Coulomb's Law on the following projects:

Lost on Wikiversity? Please help by choosing project boxes to classify this resource by:

Coulomb's Law states that

The magnitude of the electrostatic force between two point charges is directly proportional to the magnitudes of each charge and inversely proportional to the square of the distance between the charges.

$F = k_0 {q_1q_2 \over r^2}$

Where:

$F \$ is the magnitude of the force exerted,

$q_1 \$ is the charge on one body,

$q_2 \$ is the charge on the other body,

$r \$ is the distance between them,

$k_0 = \frac{1}{4 \pi \epsilon_0} \approx$ 8.988×10⁹ N m² C^-2 (also m F^-1) is the electrostatic constant or Coulomb force constant, and

$\epsilon_0 \approx$ 8.854×10⁻¹² C² N^-1 m^-2 (also F m^-1) is the permittivity of free space

When this equation is utilized its important to note that if the force results as a negative number, then the force is attractive, if it results as a positive number, then its repulsive. So for instance, if both charges where positive or if both where negative, the force would be positive and thus repulsive; if one was positive and the other negative, the force would be negative and thus attractive. A more mathematical way to explain this would be using vectors.

The full vector form of the equation reads as:

$\vec F_{2,1} = k_0 {q_1q_2 \over r^2} \hat r_{2,1}$

Where:

F 2,1

is the force vector acting on charge 2, coming from charge 1

$\hat r_{2,1}$ is the unit vector representing displacement ending at charge 2, coming from charge 1 (starting at 1, ending at 2)

This vector form is a little more useful since it contains more data. The difference now is that if both charges are positive, the force vector will face outwards, meaning that charge 2 will experience a repulsive force pushing it away from charge 1. If one of the involved charges are negative, the force vector will flip directions and face inwards, thus charge 2 will experience a force pushing it towards charge 1. Often however, it easier to neglect the vector form while calculating. That means that you solve the equation simply on a scalar level. When you get your results you will decide if the force is repulsive or attractive.

[edit] see also

Coulomb's law

Coulomb's Law

From Wikiversity

[edit] see also

Views

Personal tools

Search

Navigation

Community

Toolbox