# How Does Superposition Principle Apply to Forces in a Three-Charge System?

• wiskeywiz
In summary, the problem involves two identical point charges (Q=3uC) situated 60cm apart on the y-axis and a 2uC point charge located at 40cm on the +x-axis. Using the equation F=kq(1)q(2)/r^2, the force between the two charges on the y-axis is calculated to be 0.225N. However, this value does not have an effect on the 2uC charge. The solution involves using the principle of superposition and finding the force on the 2uC charge by treating it as a triangle formed by the lines connecting it to each Q and using the diagonal length as R in the equation F=KQQ/R^2. The
wiskeywiz

## Homework Statement

Two identical point charges (Q=3uC) are situated 60cm apart on the y-axis equidistant from the origin. A 2uC point charge lies at 40cm on the + x-axis. What is the magnitude and direction of the net force on the 2uC charge.

F= kq(1)q(2)/r^2

## The Attempt at a Solution

i figured the force between the two charges on the y-axis to be .225N using the above equation, but i do not see how that value is going to have any affect on the 2uC charge.

use superposition

if you draw lines from each Q to the 2uC you will see you have a triangle in order to find the force effecting 2 you need to use that diagonal length as R for F=KQQ/R^2 you will be able to find this pretty easily because you'll see the right triangle forming at the origin.

The value from each will be the same because the distance is the same, so you should find that its just twice as large as one side.

HINT: What does the principle of superposition say?

Edit: Beaten to it ...

## 1. What is electrostatics?

Electrostatics is the study of stationary electric charges and the forces they exert on each other. It is a branch of physics that deals with the behavior of electric charges at rest.

## 2. What is Coulomb's Law?

Coulomb's Law is a fundamental law of electrostatics that describes the magnitude and direction of the electrostatic force between two point charges. It states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

## 3. How is Coulomb's Law expressed mathematically?

Coulomb's Law is expressed as F = k(q1q2)/r2, where F is the electrostatic force, k is the Coulomb's constant (8.99 x 109 Nm2/C2), q1 and q2 are the magnitudes of the two point charges, and r is the distance between them.

## 4. How does the distance between two charges affect the electrostatic force?

The electrostatic force is inversely proportional to the square of the distance between the charges, meaning that as the distance increases, the force decreases. This is because the electric field spreads out as the distance increases, resulting in a weaker force between the charges.

## 5. What is the unit of charge used in Coulomb's Law?

The unit of charge used in Coulomb's Law is the Coulomb (C), which is equivalent to the charge of approximately 6.24 x 1018 electrons. It can also be expressed as the product of current and time (C = A x s).

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