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 where the particles in the medium move parallel to the direction of propagation of the wave. When we studied transverse waves we looked at two different motions: the motion of the particles of the medium and the motion of the wave itself. We will do the same for longitudinal waves.