# How Is Coulomb's Law Demonstrated with a Suspended Charged Ball?

• rindishy123
In summary, the conversation discusses using a lightweight, negatively charged ball to verify Coulomb's law. The force of repulsion on the suspended ball is given by F = W tan x, where x is the small angle of deflection. To solve for F, one must identify the forces acting on the ball and apply the conditions for equilibrium.
rindishy123
Hey...i need help...

"One practical arrangement for verifying Coulomb's law is to use a lightweight, negatively charged, freely-suspended ball. it is repelled by the negative charge on a larger sphere that is held near it, on an insulated support. the small angle of deflection, x is then measured.

The weight of the ball is W. show that the force of repulsion F on the suspended ball is given by:

F = W tan x"

I've drawn a free body force diagram, but i still can't work it out..

Start by identifying the forces acting on the suspended ball. (Hint: Three forces act on that ball.) Then apply the conditions for equilibrium: the sum of the forces must be zero. (Hint: Consider vertical and horizontal components separately.)

Ok I've got to the point where I've found that the components of N (the normal reaction force) are:

N sin x

and

N cos x

I don't study maths so could you please give me hints as to how I turn the above into F = W tan x?

I don't know what you mean by the "normal force" in this problem. Answer the questions I asked in my last post: What are the forces acting on the ball?

## 1. What is Coulomb's Law?

Coulomb's Law is a fundamental principle in electromagnetism that describes the force between two electrically charged particles. It states that the force of attraction or repulsion between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

## 2. How is Coulomb's Law related to mechanics?

Coulomb's Law is related to mechanics because it is a fundamental law that governs the behavior of charged particles in motion. It is often used in the study of mechanics to calculate the forces acting on charged particles and their resulting motion.

## 3. What are the units of measurement for Coulomb's Law?

The units of measurement for Coulomb's Law are Newtons (N) for force, Coulombs (C) for electric charge, and meters (m) for distance. In the SI system, the constant of proportionality in Coulomb's Law is measured in units of Newton-meters squared per Coulomb squared (Nm^2/C^2).

## 4. Can Coulomb's Law be used to calculate the force between non-point charges?

Yes, Coulomb's Law can be used to calculate the force between non-point charges by treating the charges as point charges located at their respective centers of mass. This approximation is valid as long as the distance between the charges is much larger than their size.

## 5. How does the strength of the force in Coulomb's Law change with distance?

The strength of the force in Coulomb's Law decreases as the distance between two charges increases. This is because the force is inversely proportional to the square of the distance between the charges. Therefore, as the distance between the charges doubles, the force decreases by a factor of four.

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