1. The problem statement, all variables and given/known data Consider a bar of length as measured in frame S. Show that the bar has the same length in frame S’, that is, show that lengths are invariant under Galilean transformations. 2. Relevant equations x'=x-vt 3. The attempt at a solution I know that t'=t y'=y z'=z so x'=x-vt The problem is that i dont understant how to make it valit with the equation, i undestant that the space from th point of view of S' dilates and is not invariant .