# How quickly is momentum transferred through an object? [duplicate]

If there was a pole, that was a light year long, out in space. (Away from all physical interference.)

If we pushed one end of it, would the other end move instantly? And does it's speed depend on what it's made of?

## marked as duplicate by John Rennie, Kyle Kanos, ZeroTheHero, FGSUZ, M. EnnsJan 27 at 3:15

If the pole was made of steel then the speed of the pulse would be approximately $$8000\,\rm m\,s^{-1}$$ which is the speed of sound in steel.