Question about death by electric shock in water.

[ZappaFan]

I was thinkin about this today...

Ok, if I am in a bathtub or a pool and something electrical is thrown into the water, then I would die. But, if Im on one end of an ocean and someone throws an electical appliance into the ocean from the opposite end, then I would be ok.

Im wondering how one would calculate the 'safe zone' of electrical shock in water? Is there some kind of formula for this? I understand there are variables to take into account, but...

Does anyone know?

[Mantikore]

Im sure there are more than a few people capable of posting a more educated response about electricity, but the ultimate thing you would want is to create an equation for the amount of current passing through the heart. Youll probably have to take into account the resistance of the body (a function on resistivity of the tissue and amount of tissue), resistance of the water (function of the resistivity of water (varies with ion concentration) and amount of water), location of you with respect to the earth, as well as the shape of the water container youre in.

[RealGangstaAssNigga]

Manti's right (as usual) in that there are far too many unknown variables. If you were to simplify every component of the system to something uniform and general, you could hypothetically calculate the combined impedance, create an equivalent circuit with the resistances expressed as functions of distance, and then solve for the distance based on source-impedance relationships.

[crazzyass]

What determines injury from electricity is amps, which is the potential difference(voltage) of the thing you're tossing in divided by the resistance of the medium it's traveling through. Voltage would be given, so we have to look at resistance.

A general formula for resistance is:

R = (p*l)/A

where p is resistivity, l is length of the resistor (in this case, the distance between you and the voltage source), and A is the cross-section of the medium.

Right off the bat, we see that the math for this is nearly impossible. Since water itself doesn't conduct electricity, it is highly dependent on the ionic content and concentration of the water. Also, the ocean is not a wire or linear rod or anything of the sort, which is what the general formula mainly address. The voltage source would have 3D medium around it, and frankly I don't know what would happen here. I haven't studied how electricity behaves if it's surrounded by a conducting medium. Does it dissipate out like a wave? Pick one point and travel through like lightning through air? Shit itself and die from confusion? No clue.

Formulating an equation would require probabilistic math and lots of data and lots of

However, we can still examine the general formula and use it as a starting place.

Resistance is directly proportional to distance. Doubling your distance doubles your resistance. So it's easy enough to do the math on this to rough out the estimate. Find whatever the amps are in a pool, work back for the resistance, then keep increasing the distance until the amps fall below a lethal range. That doesn't take into account the cross-section, but that's intended pretty much 100% for wires or concentrated conductors. I'm not sure how to adapt it to a 3D medium, like I said.

Sorry I wasn't of more use. Just stay out of all electrified water, I guess.

[Issue313]

Doesn't current need to pass through you on the way to a ground? I guess no current escapes through the ceramic tub, so it all depends on if the body provides a lower resistance path to the current than the surrounding water. I think.

[DJ Meaty Cheeks]

Throwing an appliance in water doesn't work that well. You need to force your body to be the only low resistance path to the ground, like sticking a fork in the socket while sitting in the bath. That'd fuck you up hard, maybe lethal.

[crazzyass]

Originally Posted by Alpheus

Throwing an appliance in water doesn't work that well. You need to force your body to be the only low resistance path to the ground, like sticking a fork in the socket while sitting in the bath. That'd fuck you up hard, maybe lethal.

Definitely lethal. Being soaked in water can reduce your body's resistance by a huge factor. Shocks that would just hurt when dry can kill when you're wet.

[moron]

Originally Posted by crazzyass

Shocks that would just hurt when dry can kill when you're wet.

[Mantikore]

Originally Posted by Alpheus

Throwing an appliance in water doesn't work that well. You need to force your body to be the only low resistance path to the ground, like sticking a fork in the socket while sitting in the bath. That'd fuck you up hard, maybe lethal.

I dont think it absolutely needs to be necessary to be in the path of least resistance in this case. It would be true if you were talking about getting hit by lightning, since air is a relatively poor conductor compared to lighting rods/trees/people. With water however, the entire medium is conductive. There is still a linear path where the resistance from charge source to sink is the smallest, but the charge doesnt only go through there, and does spread out. Im sure there are mathematical formulae out there to calculate how much there is.

But a better way to understand it intuitively is to use the water flow analogy. Pouring water down a slope causes the water to move the quickest in the middle of the stream, but slows down on the edges.

[DJ Meaty Cheeks]

Originally Posted by Mantikore

I dont think it absolutely needs to be necessary to be in the path of least resistance in this case. It would be true if you were talking about getting hit by lightning, since air is a relatively poor conductor compared to lighting rods/trees/people. With water however, the entire medium is conductive. There is still a linear path where the resistance from charge source to sink is the smallest, but the charge doesnt only go through there, and does spread out. Im sure there are mathematical formulae out there to calculate how much there is.

But a better way to understand it intuitively is to use the water flow analogy. Pouring water down a slope causes the water to move the quickest in the middle of the stream, but slows down on the edges.

I'm sure you'd get a horrible shock either way, but to be sure you got good and dead I think it'd be best to sit in the tub and stab some metal into the socket.

[jkim4007]

subbing.

[Anders Hoveland]

Originally Posted by ZappaFan

Im wondering how one would calculate the 'safe zone' of electrical shock in water? Is there some kind of formula for this?

It the conduction field would typically not expand beyond a circle between the two points of electrical contact. In other words, if you are in the bath tub on one side, you are unlikely to be electrocuted if two wires are placed close together in the other side. Except at much higher voltages, the electrical current tends to only flow from negetive to positive. If someone throws a hair dryer into your bath tub and you are on the other side of the tub, you a probably not going to be electrocuted. The danger is if you try to hold a hair dryer that is plugged in when you are wet. Part of the cord could get submerged in water, and there might be a tiny crack in the cord's insulation. The current could conduct through the bath tub, into your body, into your hand, and back to the hair dryer. If the circuit is completed, you will be electrocuted.