text: what is th meaning of locomotives and dimensional analysis?   steam locomotives were huge railroad engines that drew long "trains" of railroad cars.  the word locomotive stems from latin locus (place) + motio (motion).  dimensional analysis is used to test scale models of steamships (etc.) that can be towed in model tanks to discover how the full-sized ship will perform (before it is built!).  for example, water exhibits a surface tension that may have nil effect on a large ship but must be accounted for on the model to correctly interpret test results.