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Physics/How many amperes are instantly lethal?


Hi! I was wondering how many amperes are immediately lethal so that there's literally no chances of survival? I've read that 210 amperes are instantly lethal and leave virtually no chances of survival. Is 210 amperes really that lethal? Because I was told that you can get that much amperes from a motor vehicle starter motor if you're not careful.

There's no answer to that question for several reasons.  I can take way more than that in a static shock from a Van de Graaf generator and not be hurt at all.  A continuous dose (your term immediately is ill-defined) of 100 Amperes across my heart for a few seconds would kill me.  Where is this shock?  How large is the person?  What is "immediately," in nanoseconds or microseconds or milliseconds...or seconds?  How is it applied, though dry skin or wet?  Is it a child, an old person, or someone of average adult size/health?  Do they have a nervous condition?  I'm going to assume an adult in average health, but that still leaves all the questions as to the application site/length of the shock.  You can kill someone with a D-cell battery if you do it right.

These are some of the variables you need to account for.  Feel free to re-ask.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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