Why do our bodies stay neutral after combing our hair?

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Homework Help Overview

The discussion revolves around the phenomenon of static electricity generated when combing hair, specifically questioning how the body maintains a neutral charge despite the transfer of trillions of electrons between hair and a comb. Participants explore the implications of this electron transfer and the concept of charge neutrality in the human body.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the significance of the number of electrons transferred and whether this amount is sufficient to affect the body's overall charge. Some question the grounding effect and the role of surrounding ions in maintaining charge neutrality. Others reference personal experiences with static electricity and its implications for charge storage in the body.

Discussion Status

The conversation is ongoing, with various interpretations being explored regarding how the body interacts with static electricity. Some participants suggest that the body can hold a charge, while others propose that the system remains neutral due to the closed circuit formed by the hair, comb, and body.

Contextual Notes

There are mentions of classroom teachings and demonstrations related to static electricity, as well as anecdotal evidence of static shocks experienced in everyday situations. The discussion includes references to the effects of environmental conditions on static charge generation.

Efast
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**This is more a general understanding question rather than a homework question**
1. Homework Statement

So when you comb your hair trillions of electrons get transferred from your hair to your comb. So when trillions of electrons go missing how is your body able to maintain a neutral charge?

Homework Equations


I'm not certain that your body maintains a neutral charge; it was just said by my teacher in class.

The Attempt at a Solution


Perhaps because your grounded?
With respects to the size and amount of electrons, perhaps a trillion of them is not very many so your body can balance it.
 
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You have heard "crackling" from your comb? In dry weather in winter?
 
Even with millions of electrons being transferred from you to the comb it is pretty insignificant as a single electron has a minuscule charge and even millions do not make a huge difference
When you comb your hair or take off a shirt and it rubs against your hair electrons are transferred from you to the object, or the other way around perhaps, but most the time they jump back in order to even out the charge
This is wear static electricity comes from
It is not always felt as most the time the electrons are too few to cause any physical sensation but in cases like this there are enough to at least cause one to hear a soft crackling while combing their hair
So in short the charges will automatically balance and the electrons will hope from object to object in order to do so
 
Efast said:
Perhaps because your grounded?
Certainly, if you are grounded that would explain it easily.
Even if you are not grounded, there will always be ions in the air around you. If you become positively charged, what will happen?
 
The hair raising demo with a Van De Graaff is done while the student stands on an insulating platform.
 
Haven't you ever rubbed your shoes on the carpet, and touched somebody's hand to give them a static shock? Your body is definitely storing charge.

It is fairly common for electronics companies to provide a budget for employee training and static protective gear (grounding, treated smocks, ionizers, static safe containers, etc.) to prevent damage to electronic components from static discharge. The voltage generated by certain simple tasks can be surprisingly high. Below is a sample I found. I believe it was saying that a 3000 V static shock is too low to even be felt. But some static-sensitive components can be damaged by much lesser voltages.

Walking across a carpet: 1,500 to 35,000 Volts
Crossing your legs: 300 Volts
Walking over an untreated vinyl floor: 250-12,000 Volts
Working at a bench: 700-6,000 Volts
Vinyl envelope for work instructions: 600-7,000 Volts
Picking up common plastic bag from bench: 1,200 - 20,000 Volts
Work chair padded with polyurethane foam: 1,500 - 18,000 Volts
Touching a door knob or metal object: 1,500 to 35,000 Volts
Standing up from a chair: hundreds of Volts
 
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I would think that scuffing your shoes on the carpet and drawing a spark comes about by the insulating shoes getting charged and inducing a charge on your body, that is by pushing the conduction electrons away from your feet.
You can then draw a spark from a sharp point on your body by sticking your finger out.
 
Efast said:
So when you comb your hair trillions of electrons get transferred from your hair to your comb. So when trillions of electrons go missing how is your body able to maintain a neutral charge?

I'm not certain that your body maintains a neutral charge; it was just said by my teacher in class.

I will be the first to admit that I don't know a lot about the process of static generation. I was addressing whether or not the body can hold a charge. But perhaps the point your teacher was making was that in the case of combing your hair, your hair and the comb and your body all make up a closed circuit and therefore, the overall net gain/loss is neutral. That may be a valid point.
 

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