Triangle Electrostatics Problem

In summary, the problem involves three positively charged particles forming an equilateral triangle and the task is to find the net force on each particle. Using the equation F = (kQ1Q2)/(r^2) and considering both charges influencing the third, the magnitude and direction of the net force can be calculated. The direction of the force is away from the center due to the repulsion of positive charges. It is important to break down the forces into horizontal and vertical components and use trigonometric functions to compute them. The final result should be 19.0 N away from the center.
  • #1
saintv
7
0

Homework Statement



Three positive particles of charges +7.0 uC are located at the corners of an equilateral triangle of side 20 cm. Calculate the magnitude and direction of the net force on each particle.

Answer: 19.0 N [AWAY FROM THE CENTRE]

Homework Equations



F = (kQ1Q2)/(r^2)

Where:

k is the Electrostatics Constant - 9 x 10^9 Nm^2/C^2
Q1 and Q2 are the charges in (C)
r is the separation in (m)
F is the Electrostatics Force in (N)

The Attempt at a Solution



Er, so I calculated the force on one of them from another, see below:

F = (kQ1Q2)/(r^2)
= [(9 x 10^9 Nm^2/C^2)(7.0 X 10^-6 C)(7.0 X 10^-6 C)]/(.20m)^2
= 11.0 N

And that's where I'm stuck: I have absolutely no idea how I would even obtain a number close to 19.0 N!

What I do understand is the direction: by [AWAY FROM THE CENTRE] they mean that because they are all positive charges, they will all repel away from one another- right? Do correct me if I'm wrong.

I really do appreciate it!
 
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  • #2
You need to consider both charges influencing the third. Hint: you need to resolve the forces into their horizontal and vertical components and the horizontals are oppositely directed so cancel out.
 
  • #3
Technically, all of the forces acting on the charge are opposite another- so by that logic, wouldn't they all cancel out?

I truly do not understand. :-(
 
  • #4
No, if the forces have the same sign and are operating in the same direction they add.

You have studied vectors a bit, right? Forces are vectors and the best way to add them is to break the forces down into horizontal and vertical components? See my picture, the red and blue arrows are the components. Equilateral triangles have what angles? Use sin, cos functions to compute the components then add, paying attn to sign! There are two balls each effecting the third, so my picture isn't complete.

triangles.jpg




That help?
 

Related to Triangle Electrostatics Problem

1. What is a Triangle Electrostatics Problem?

A Triangle Electrostatics Problem is a type of physics problem that involves calculating the electric forces and fields at different points on a triangle formed by three charged particles. This problem is commonly used to test understanding of the principles of electrostatics and Coulomb's Law.

2. How do you solve a Triangle Electrostatics Problem?

To solve a Triangle Electrostatics Problem, you first need to identify the values of the charges and the distances between them. Then, you can use Coulomb's Law to calculate the electric forces between each pair of charges. Finally, you can use vector addition to find the net electric force and electric field at a specific point on the triangle.

3. What is Coulomb's Law?

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

4. What are the units for electric force and electric field?

The SI unit for electric force is Newtons (N), while the SI unit for electric field is Newtons per Coulomb (N/C). However, both can also be expressed in terms of other units, such as Joules per meter (J/m) for electric field.

5. What are some real-world applications of Triangle Electrostatics Problems?

Triangle Electrostatics Problems have applications in many areas of science and technology, such as electrical engineering, particle physics, and astronomy. They can help scientists and engineers understand the behavior of electric charges and design systems that utilize electric fields, such as electronic devices and particle accelerators.

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