Electric Shocks

helimachoptor

Was watching the film "Taken" last night with Liam Neeson.

In one scene he puts 2 metals bars into a guys legs and hooks up jumper cables to these rods and to the mains and proceeds to turn on the juice.

Now the questions I have is how long could a person survive receiving an electric shock like that?

Don't worry I don't plan on torturing anyone!!

DrIndy

in theory, yes.

Turning on the juice would result in severe burns of the tissue through which the current passes - paralysing muscles including breathing muscles - but if the duration was short, then the breathing would restart in time to prevent deprivation of oxygen.

The key thing too is that a shock of that magnitude could also stop the heart - but if this did not happen or if the heart were able to spontaneously restart - then yes you could survive this in horrible pain and deep tissue burns.

You would probably have massive muscle breakdown though and get kidney failure.

helimachoptor

Thanks DrIndy

nesf

It depends on the flow of current through the person and the path the current takes to a large extent from what I remember of this. If someone was lying on a wooden bench and you "turned on the juice" it'd be very different to if they were lying naked on the bare ground.

Similarly if someone was standing there'd be a difference to the current being introduced at the knee then to their shoulder because of the path the current will take. What you really don't want to happen is for current to flow from arm to arm if you ever get a shock (i.e. your two hands are holding conductors at two different voltages so current flows between them through you and across your chest/heart).

If the guy was standing then the current might pass straight down his leg giving him extremely severe burns and damaging everything on it's path down but he might avoid heart failure if no current reaches it from my understanding of what happens with electric shocks and the body.


In practical terms you've got to remember that any kind of short circuit like that in a home system would either trip the circuit breaker or blow the main fuse in the box. So the current wouldn't stay on for much longer than a fraction of a second if he just hooked it up to the mains. But that doesn't make for good TV.


Edit: To explain in a bit more detail. What kills you is how much current passes through you and the path it takes to the ground. The amount of current that flows for a given voltage depends only on the resistance of a material to current flow. This is why you get a bigger shock when standing barefoot than when you're wearing rubber soled shoes (rubber is a good insulator and increases the resistance of your body reducing the current flow) or why it's less dangerous (but still dangerous!) to get a shock from the mains if you're standing on a wooden chair at the time versus standing barefoot on a metal stool. Voltage under a certain amount won't give you a shock you can feel because it can't overcome the body's resistance but mains voltage can easily do so.

Current flows along the shortest path of least resistance to ground (or to another point of lower voltage, i.e. in the two phase electric system in your home grabbing a live wire and a neutral wire in different hands can be more lethal than just grabbing the live wire alone) so if you get a shock in the leg when standing the current will not pass across your heart etc.

In summation, your survival of an electric shock depends mainly on two factors, the path the current will flow across and the amount of current that's passing through the body at any given second. The second being dependent on a huge number of factors from exactly what shoes you're wearing and what you're standing on to your body's level of hydration and such. At very high voltages (much higher than mains voltage) the second part becomes meaningless since anything short of standing on specific high voltage insulating material of sufficient height will mean a lethal ampage will flow through the body. Which is if you want to torture someone you don't use an extremely high voltage.

DrIndy

nesf - you seem to know faaaaaar too much about this.

nesf

DrIndy wrote: »

nesf - you seem to know faaaaaar too much about this.

I used to work with high voltage machinery many years back and got curious about how it could kill me and how it would do it..

helimachoptor

nesf wrote: »

I used to work with high voltage machinery many years back and got curious about how it could kill me and how it would do it..

I won't be getting on your bad side

Capt'n Midnight

It's Volts that jolts, and mills that kills. You can feel the hairs on your arms stand up when near a old CRT telly. Works for cats too, don't turn off a TV while holding a cat against it ! Anyway the voltage off the TV you feel could be up to 30,000 Volts but no current so it's safe apart from getting scratched by a cat. IIRC a few milliamps across the heart can break the rythm and kill you. And it only needs maybe 20 Volts. If there is current going from leg A to leg B then while your gonads may glow bright blue, your heart is not in the direct path so would not get the same blast. Normally it's your hands that touch live things and a current going from arm A to arm B would pass over your heart. Lookup stuff on the electric chair and even with shaved head and electrodes designed for the purpose death can take a few minutes. You would litterly be fried After an initial shock with electircity you may perspire so your electrical conduction goes up and you conduct more so you can't assume that dry skin will save you. Mains in the US is only 110V so a lot safer than the 230V we have over here too.