Electron Velocity In Tubes

[Nick]

As one goes in, another one fires out of the other end ...

Newton's Cradle...

Err ... we were simulating electron flow in a length of wire which, in itself, is useless as an oscillator (unlike Newton's Cradle ...)

Cross purposes, maybe. Newton's Cradle is designed to demonstrate the law of conservation of momentum - the fact that the end ball(s) swing out to repeat the process is incidental - it was never intended to be an oscillator - its all about the transfer & conservation of momentum.

The effect is identical in every way to that you described with the row of coins: cf. https://en.wikipedia.org/wiki/Newton%27s...his_effect

Electron == steel ball == coin. As long as they are in straight line, touching & have the same mass, it works.

The truth is that it's a very simplistic explanation of how current travels through a conductor - at an atomic level its just a tad more complex... (and not a lot to do with the transfer of momentum!)