newtons cradle

phlegmy

hey dudes

i read in a book that when an electric current flow that the electrons move preety slow [maybe 1mm/s i'm not sure]
now i also know electricity travels at the speed of light (ideally) so that an electron c*1s away will take 1s to start moving after i close the circuit

so i was thinking about a newtons cradle
if the moving ball hits the next ball at say .05m/s and all the balls add up to .05m then obviously it wont take a full second for the last ball to move, so how fast does the "impulse"? move through the stationary balls . i've a feeling its the speed of sound (in the medium of the balls) is that right?

russ_watters

It is indeed the speed of sound.