Question

Occasionally, people who gain static charge by shuffling their feet on the carpet will have their hair stand on end. Why does this happen?

Short answer

Answer: A person's hair stands on end due to the repulsive forces between the negatively charged strands of hair, which is caused by the electrostatic interaction between charged particles. This occurs when a person shuffles their feet on the carpet, transferring electrons from the carpet to their body, making them negatively charged. The low conductivity of the materials involved maintains the imbalance of charges, causing the hair to repel each other and stand on end.

Step-by-step solution

Review of Static Electricity

Static electricity is the result of an imbalance of electric charges within or on the surface of a material. When two objects are rubbed together, electrons are transferred from one object to another, causing one object to become positively charged and the other to become negatively charged.

Generating Static Electricity through Shuffling

When a person shuffles their feet on the carpet, they are rubbing their shoes against the carpet fibers. This friction causes electrons to be transferred from the carpet to the person, making the person's body negatively charged.

Hair Standing on End

When the person's body gains a negative charge, the electrons in their hair are repelled by the excess electrons on their body. This repulsion causes the individual strands of hair to repel each other, making them move apart and stand on end.

Importance of Conductivity of Materials

The conductivity of the materials involved in the interaction is important. In this case, the carpet, shoes, and hair all have low conductivity, meaning they do not easily allow the flow of electric charges. Therefore, the negative charges remain confined to the person's body and hair, causing the repulsion effect and making the hair stand on end.

Conclusion

A person's hair stands on end when they gain static charge by shuffling their feet on the carpet because of the repulsive forces between the negatively charged strands of hair. This repulsion is due to the electrostatic interaction between charged particles, and the low conductivity of the materials involved in the interaction maintains the imbalance of charges.