| MadSci Network: Other |
Hi jade!
A shock from a car door is painful, so it
seems as if there must be lots
of energy involved. Actually, there is not.
The electric spark is painful because the
energy is concentrated upon a tiny spot on
your skin, and it gives you a small burn.
If the same energy was spread out over your
whole finger, you wouldn't feel any pain.
The actual energy is less than the energy
of a gentle slap. But what happens when
you are slapped by a hand which is holding
a sharp needle? Yow! It hurts alot when the
energy is all concentrated into a tiny
place on your skin. "Static" sparks are like
being poked with a needle.
Try this: next time you're riding in a
car, and the weather is dry, find a quarter
or other small metal object. When you leave
the car, hold the coin between your fingers
so the edge is sticking out. Touch the edge
of the coin to the metal car door. You'll
hear the small spark, but you won't feel a
thing. The edge of the coin took all the heat.
Another one: go to an electronics store
(such as Radio Shack in the USA) and buy
a neon pilot light. NE-2 or NE-2H bulbs work fine.
On a dry day, scuff your shoes on the carpet
for awhile, then hold the neon bulb by one
wire while you touch the other wire to a
person or to a large metal object. The bulb
will give out a flash of orange light.
Can "static electricity" be used to do some real work? Sure, but you have to generate it continuously. Here are plans for a static electric motor:
ELECTROSTATIC POP-BOTTLE MOTOR
http://www.amasci.com/emotor/emotor.html
When your clothes rub against a car seat, they become charged, and when you leave the car, your body's voltage rises to a very high level. It takes about 3,000 volts to make a painful spark, and when the weather is very dry, the voltage can be as high as 50,000 volts.
HUMANS AND SPARKS
http://www.amasci.com/emotor/zapped.html
MORE ABOUT "STATIC"
http://www.amasci.com/emotor/statelec.html
Try the links in the MadSci Library for more information on Other.