What does it mean to be financially responsible? It's a complex question with a complex answer, but at its core is a simple truth: To be financially responsible, you need to live within your means. And to live within your means, you must spend less than you make.
longitudinal axis. A straight line running fore and aft through the center of gravity. It is horizontal when the airplane is in the rigging position. The aircraft rolls about this axis. See axes.
A longitudinal wave is a wave in which the particles of the medium are displaced in a direction parallel to the direction of energy transport. A longitudinal wave can be created in a slinky if the slinky is stretched out horizontally and the end coil is vibrated back-and-forth in a horizontal direction.