Is it possible to receive an electric shock when you stop touching something?
Is it possible to receive an electric shock when you stop touching something?
I seem to remember as a young child being told that it is safe to touch a Van de Graff generator (for the hair demonstration), but that if you let go before it is safe you will get a nasty shock. I know a bit more about electricity now, and I'm a little skeptical now. Is it possible to get a shock from letting go of something?
You get a shock when there is a big protentional energy difference between your body and something else. Either high or low.
So the "let go before its safe" means they want to stop the generator, and ground it, so the electrons leave though a path that isn't your body, to avoid the shocks
Why wouldn't the electrons go to ground through your body while you're touching it?
They can and do, but you feel the zap when there's an arc. If there's current moving though your body without an arc, it feels like your muscles vibrating or cramping, depending on whether it's AC or DC, mostly. After all, your muscles are activated with electrical signals.
Usually for a Van de Graf demonstration The person touching it has some level of electrical isolation from the ground. Be it their shoes or something else. If they were touching the ground directly or a piece of metal they would constantly be passing the electrons through and they wouldn't get that whole hair raising effect.
I am not expert, but seems plausable. Shock comes from high voltage electric charge jumping from metal to skin. If you press it, you are part of the electric charge. If you are far away, charge cannot jump. Problem is only when you are couple of centimeters close to it. AFAIK, this is not current, but electric discharge, I think it cannot kill you (it is just very unpleasant), but maybe someone else knows better?
Thing that confuses me is that when you let go, you should have the same charge as the generator. No charge difference, no arc. Unless I'm wrong about something, which I probably am (hence my confusion).
Yeah, if you move your hand around on those things you'll get a static shock, it's going to hurt, but it won't kill you. If you watch those demonstrations they have a pole they ground the generator out with.
If you're in some kind of science experiment where you're being conditioned to not stop touching something: Yes.