OpenStax College Physics, Chapter 20, Problem 88 (Problems & Exercises)

This is College Physics Answers with Shaun Dychko. A person in a bathtub touches the metal case of a radio and we are told that the resistance of the path from the person through the tub to the ground is 4000 ohms and it's asking what voltage should the case of the radio have to cause ventricular fibrillation? So we need to look up in table [20.3], what current would cause ventricular fibrillation and that would be from 100 to 300 milliamps. So let's take 100 because we'll take the lowest possible voltage corresponding to the lowest possible current and we'll use 100 milliamps as the current in this question so that's 100 times 10 to the minus 3 amps. So the voltage then is current multiplied by resistance so that's 100 times 10 to the minus 3 amps times 4000 ohms, which is 400 volts. So the case of the radio would need to have a voltage of 400 volts compared to ground in order to cause ventricular fibrillation in this person.