# I need a lot of help with Coulomb's Law and Electric Fields? Need HELP

• devilz_krypt
In summary, the conversation is about someone needing help with understanding Coulomb's Law and Electric Fields. They have 3 questions they did not understand, including finding the magnitude and direction of an electric field for a small object, finding the acceleration and distance traveled for an electron in an electric field, and locating the point where the electric field is zero for two charges on the x-axis. They have multiple solutions for each problem and are looking for the best solution for each one.
devilz_krypt
I need a lot of help with Coulomb's Law and Electric Fields?? Need HELP!

## Homework Statement

Here are 3 of the 25 questions the i did not understand, in regards with electric fields and Coulomb's Law.

1. A small object of mass 2.0 g and charge of 1.8x10^-7 C "floats" in an electric field. Find the magnitude and direction of the field.

2. An electron is accelerated by a constant electric field of magnitude 300 N/C.
A) Find the acceleration of the electron.
B) How far will the electron travel in 3s?

3. Two charges lie along the x-axis. If q1= -9.0x10^-6 C is at x= 6m and q2= -8x10^-6 C at x= -4m, locate the point at which the electric field will be zero.

Please help me finish my test review, i have been very confused ever since we start Coulomb's Law and Electric Fields.

## Homework Equations

F= ((k)(q1)(q2))/(r^2)
E= (k)(q)/(r^2)
F= qE

The reason I didnt submit my solution is because i have about 5 different solutions for each problem.

Submit the solution you think is best for each one.

I understand that Coulomb's Law and Electric Fields can be challenging concepts to grasp. It is important to remember that these concepts are fundamental to understanding electricity and are used in many applications, such as electronics and power generation.

In order to better understand Coulomb's Law and Electric Fields, it is important to review the equations and principles involved. Coulomb's Law states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. This can be represented by the equation F= (k)(q1)(q2)/(r^2), where k is the Coulomb's constant, q1 and q2 are the charges of the objects, and r is the distance between them.

Electric Fields, on the other hand, are defined as the force per unit charge that a test charge experiences at a given point in space. The equation for Electric Fields is E= (k)(q)/(r^2), where q is the test charge and r is the distance from the source charge.

Now, let's address the questions you have listed.

1. In order to find the magnitude and direction of the electric field in this problem, we can use the equation E= (k)(q)/(r^2). Since the object is "floating" in the field, we know that the net force on the object is zero. This means that the force due to gravity must be equal and opposite to the force due to the electric field. We can set up the equation Fg= Fe and solve for the electric field (E). Plugging in the values given, we get E= (6.67x10^-11 N*m^2/C^2)(1.8x10^-7 C)/(2.0x10^-3 kg)^2. This gives us an electric field of 1.5x10^4 N/C directed towards the positive charge.

2. A) To find the acceleration of the electron, we can use the equation F= qE. Since the electron has a charge of -1.6x10^-19 C, we can plug this into the equation along with the given electric field of 300 N/C. This gives us a force of -4.8x10^-17 N. Using Newton's second law (F=ma), we can solve for the acceleration (a). This gives us an acceleration of -3.

## 1. What is Coulomb's Law?

Coulomb's Law is a fundamental law in physics that describes the relationship between electric charges. It states that the force between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

## 2. How do I calculate the force using Coulomb's Law?

The formula for calculating the force between two charged particles using Coulomb's Law is F = (k * q1 * q2) / r^2, where F is the force, k is the Coulomb's constant, q1 and q2 are the charges of the two particles, and r is the distance between them.

## 3. What are electric fields?

Electric fields are regions in space where a charged particle experiences a force. They are represented by vectors and their direction is determined by the direction of the force on a positive test charge placed in the field.

## 4. How do I calculate the electric field using Coulomb's Law?

To calculate the electric field at a point due to a single point charge, we use the formula E = (k * q) / r^2, where E is the electric field, k is the Coulomb's constant, q is the charge of the source particle, and r is the distance between the source particle and the point of interest.

## 5. Can Coulomb's Law be used to calculate the force and electric field for multiple charges?

Yes, Coulomb's Law can be used to calculate the force and electric field for multiple charges by using the principle of superposition. This means that the total force or electric field at a point is the vector sum of the individual forces or electric fields due to each charge.

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