# Electric Charge Applied on Two Wires of Electroscope?

• TrivialPants
In summary, the problem involves a large electroscope with 78-cm-long wires and 24-g spheres at the ends. When charged, most of the charge is found on the spheres. The wires are at a 26° angle and the total charge Q needs to be calculated. To solve the problem, the mass of the wires is ignored and the forces acting on each sphere need to be analyzed. This will help in finding the electrostatic force which can then be used with Coulomb's law to calculate the total charge Q.
TrivialPants

## Homework Statement

A large electroscope is made with "leaves" that are 78-cm-long wires with tiny 24-g spheres at the ends. When charged, nearly all the charge resides on the ends of the spheres. (See diagram attached)

If the wires each make a 26° angle with the vertical, what total charge Q must have been applied to the electroscope? Ignore the mass of the wires?

Diagram of the Electroscope:

## Homework Equations

What does it mean to ignore the mass of 24g? Does that mean that I can find the charge by finding the distance between the two points?

## The Attempt at a Solution

I split the triangle into two right triangles. Then I used the trig properties to deduce that:

sin26° = opp/hyp = .4387, opp/78cm = .4387 = opp =.4387*(78cm) =34cm

Now using this data, I would input the distance between the repelling positive charges into the Coulombs Law:

F = (k|Q1||Q2|)/(r12)^2 Where k = 8.988x10^9 N*m^2 / C^2 and r = 68 which is derived above
(34*2) = 68 cm or 68*10-2m

How do I find the value of Force? I will be needing it to complete the problem this way. Thank you!

TrivialPants said:
What does it mean to ignore the mass of 24g?
You are to ignore the mass of the wire, not the spheres. You'll need their mass to solve the problem.

TrivialPants said:
How do I find the value of Force?
Analyze the forces acting on each sphere. Hint: Three forces act.

Doc Al said:
You are to ignore the mass of the wire, not the spheres. You'll need their mass to solve the problem.Analyze the forces acting on each sphere. Hint: Three forces act.
Is the method I am using thus far correct to find the value of the Q? Since there is no mention of an electric field in this problem I assume I will be using the coulombs law equation I stated above: $$k\bullet\mid Q_1\mid\bullet\mid Q_2\mid\\r_{1,2}^2$$

TrivialPants said:
Is the method I am using thus far correct to find the value of the Q? Since there is no mention of an electric field in this problem I assume I will be using the coulombs law equation I stated above: $$k\bullet\mid Q_1\mid\bullet\mid Q_2\mid\\r_{1,2}^2$$
Sure, you need to use Coulomb's law to calculate the total charge. (Note that Q_1 = Q_2 = Q/2.)

But you first need to do the force analysis to find the electrostatic force.

## 1. What is an electroscope and how does it work?

An electroscope is a scientific instrument used to detect and measure electric charge. It works by using two metal leaves attached to a metal rod, suspended in a glass jar. When a charged object is brought near the rod, it causes the leaves to repel each other, indicating the presence of an electric charge.

## 2. How is electric charge applied on two wires of an electroscope?

Electric charge can be applied on two wires of an electroscope by using a source of electric charge, such as a battery or an electric generator. The wires are connected to the source of charge, and when the source is turned on, the charge will flow through the wires and onto the electroscope.

## 3. What happens when electric charge is applied on two wires of an electroscope?

When electric charge is applied on two wires of an electroscope, the leaves of the electroscope will either repel or attract each other, depending on the type and amount of charge applied. This movement of the leaves allows us to measure the presence and strength of the electric charge.

## 4. Can the amount of electric charge applied on two wires of an electroscope be measured?

Yes, the amount of electric charge applied on two wires of an electroscope can be measured. This can be done by using a device called a Coulomb meter, which is specifically designed to measure the amount of electric charge in a given system.

## 5. What are some practical applications of using electric charge on two wires of an electroscope?

The use of electric charge on two wires of an electroscope has various practical applications. For example, it can be used in experiments to demonstrate the principles of electrostatics, or in industries such as electronics and telecommunications to test and measure the presence and strength of electric charge in different materials and devices.

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