Physics Experiment- Static Electricity

by Oren Lahav

Zap it out with physics!

Materials:

Some of the following:

Hair (your own, if you have some)
A balloon
A comb
A tap of water
Your pet (or little sibling if you have one)
A thick carpet
A door with a metal knob

The experiment:

Blow a balloon up until it's nice and round. Now rub it against your hair, or a sweater if you're wearing one. Rub it fast!
Try to stick the balloon to your pet or your little brother or sister. You can also you things like walls and any other surface- see what works best!
Since you probably messed your hair, comb it until it's nice again. Now, open up the water faucet just a bit until a really really thin stream of water comes out.
Take the comb and place it close to the water. See what happens to the stream!

Now comes the final, cool part. Take off your shoes, and rub your feet on the thick carpet all over the room for a while.
Use your finger to touch the metal knob (or your pet/sibling if you feel like it). Watch out though, they may not like it.

The physics behind the scenes:

These fun experiments may seem different, but they all have a big element in common- static electricity!

All elements are made out of atoms. Atoms have 3 components- positive protons, neutral neutrons, and negative electrons. While the protons and neutrons are relatively stationary in the nucleus of atoms, electrons are free to move about (sort of).

Now, when you rub two materials against each other, you cause electrons to move. The electrons will move from one material to another. The one material from which the electrons left will have less negative particles now, so it will be positively charged. On the other hand, the second material which the electrons moved into will become negatively charged. And just like in real life, opposites attract- so 2 different charges attract while similar charges repel.

So, we rub the balloon, thus charging it. Now, place it on your pet, wall, whatever- they're neutral, which means that the charged balloon will attract the particles in the other material, which will cause the balloon to "stick" to it.

Similarly, say we charge the comb. Tiny water particles from the stream will be attracted to it, causing the water current to bend towards the comb. If you place another charged comb near the stream, the water will bend another way.

Finally, when you walk on a carpet, you charge yourself- your whole body. You'll notice that this may cause your hair to "stand up straight", and this is because the charges want to move out of your body and neutralize it (return it to neutral). Note that this is only when the air is dry, otherwise charges can escape into the air. When you get your hand near a metal knob or some other conductive material, the charges can't wait to leave and they "jump" from your hand to the door in a form of a spark you can feel! That explains why you get small electrocutions in winter when the air is dry.

And that's almost the same way lightning works in real nature! Awesome!

Physics is cool!

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– Fri, 09 Mar 2012 11:19:27 -0000

i am a college physics teacher in ethiopia. i got your inoformation very valuable 4 my dear students. but i went to meet you and improve my acadamic status. 10 Q

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