Paper Rubbed with Wool/Fur/Silk

[soulembracer]

Homework Statement

What kind of charges will a sheet of paper have after it has been rubbed with wool or fur? with silk?

Homework Equations

none

The Attempt at a Solution

I have an idea about this, I'm just not definite with the answer. I know the paper is a good insulator if kept dry. Assuming that the paper is dry, rubbing it with wool (which is a better insulator) will separate the charges.

I've read from my book that when objects are given net charges by rubbing them against one another, both electrons and ions/charged atoms can be transferred from one object to another.

Here's where I'm confused, since both electrons and ions can be transferred, what (specifically) could be its kind of charged?

I guess the wool would have negative charges, the paper - positive charges. I just don't know if it's right, and how to justify that. And also, is it the same with silk?

Help

 

[anathema]

is appreciated!

Hi there! I can provide some insight into your question. When a sheet of paper is rubbed with wool or fur, electrons are transferred from the wool or fur to the paper. This leaves the paper with a net negative charge, since it now has more electrons than protons. This is known as the triboelectric effect.

Similarly, when a sheet of paper is rubbed with silk, electrons are also transferred from the silk to the paper. However, silk has a lower affinity for electrons compared to wool or fur, so the transfer may not be as significant. The paper may still end up with a net negative charge, but it may not be as strong as when it is rubbed with wool or fur.

To justify this, we can look at the triboelectric series, which ranks materials based on their tendency to gain or lose electrons when rubbed against each other. Wool and fur are ranked higher on the series compared to silk, meaning they have a stronger tendency to gain electrons. This is why the paper will have a stronger negative charge when rubbed with wool or fur.

I hope this helps answer your question! Let me know if you have any further questions.

 

[thomate1]

??

I can confirm that your understanding is correct. When an object is rubbed with another object, the friction between the two can cause the transfer of electrons from one object to the other. In this case, the wool or fur would have a higher affinity for electrons and would therefore gain electrons from the paper, leaving the paper with a net positive charge. This is known as the Triboelectric Effect.

As for silk, it is also a good insulator and can cause the same transfer of electrons when rubbed against the paper. However, silk has a lower affinity for electrons compared to wool, so the resulting charge on the paper may not be as strong.

To justify the charges on the paper, we can use the concept of charge conservation. This means that the total amount of positive and negative charges in a system must be equal. Since the paper gained electrons from the wool or silk, it now has a net positive charge. This charge is balanced by the negative charge on the wool or silk.

In summary, after being rubbed with wool, fur, or silk, a sheet of paper will have a net positive charge due to the transfer of electrons. The specific charge will depend on the material used for rubbing, with wool resulting in a stronger positive charge compared to silk.