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Q & A: Charged Particles: In People

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Most recent answer: 10/22/2007
Q:
Mike, thanks for answering my previous question about magnets attracting people - you asked if I wanted anything further on the subject, and I do. Does ELECTRIC charge have an effect on people (positive or negative)? If so, can a STRONG ENOUGH electric charge attract/repel a human? THANKS!
- Courthead (age 15)
USA
A:
Courthead-

It's nice to have one of these trains of thought continue.

Ordinarily, people are very close to electrically neutral overall. However, you can charge yourself up a bit by rubbing you feet on a rug, especially on a dry day. Then you can feel the charge leave as a spark when you nearly touch an oppositely charged spot. Even an overall neutral person will be slightly attracted to an electrical charge, regardless of whether it's positive or negative. The reason is that we are only neutral in total- we have lots of positive and negative ions in us, especially Na+ and Cl-, which together make ordinary salt. If you're near a + charge, your - ions will flow toward the charge and your + ions will flow away. Since you are now negative near the charge (where the force is strong), and positive farther away (where the force is weak), you will feel a net attraction to the charge. Incidentally, if a person is "charged up" either because he or she has shuffled his or her shoes on a carpet on a dry day, or because he or she is close by another charge, (as above), then there will be some noticeable, if small, consequences. Each hair will get the same charge as the others because of the overall net charge, and therefore repel the other hairs. This will make the hair stand up on end. It's a popular demonstration item with the Physics Van's tours. Here's a picture of a little girl whose hairs is electrostatically repelling each other while she is touching a Van de Graaf generator: .

Mike

(published on 10/22/2007)

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