I understand that there are three velocities in play in a circuit (I haven't studied Physics past high school so give me some rope)
v1: the velocity by which the electrical field propagates through the conductor (equal to the speed of light)
v2: the velocity of the free electrons in the wire. Free electrons move around randomly in a sort of Brownian motion at speeds in the order of 1000 Km /s. When no voltage is applied on the wire this random motion results in no aggregate movement of electrons.
v3: a constituent velocity vector, consistent (not random) by which the free electrons move in the direction of the current. This is very small in the order of mm or even μm / s. This vector is added on the vectors of the "Brownian" motion and results in the actual flow of electrons.
My question is: when I am electrocuted which electrons actually kill me?
- electrons already existing inside my body that start to move under v3. This seems unlikely as they were previously moving at v2 with no harm. Also my body is not a conductor so free electrons inside my body don't make sense.
- electrons from the wire that pass into my body. Given that the additional speed they acquire because of the field is very small I don't see why they couldn't previously enter my body when I touched the wire (under no voltage). Also, v3 is very small so the experience of the electrocution in that scenario would have been that my finger is shocked first, then my hand, then my arm, then my shoulders. Instead an electric shock feels instantaneous.
And I haven't even considered yet that we are mostly using alternating current so no actual, net, flow of electrons into my body occurs. Can somebody clear this confusing mental model for me?