Answer:
Sound waves in liquids and gases involve alternating compression and rarefaction of material along a line defining the direction of propagation of the wave. These waves are known as longitudinal waves, and of course exist only in a medium that can be compressed and rarefied. In solids, sound energy also produces longitudinal waves, but it can also produce transverse waves, in which compression and rarefaction occurs perpendicular to the direction of propagation. These two waves propagate at different speeds, a phenomenon that is most noticeable in earthquakes. The first wave gives notice that the quake is coming, the second one does the damage. The time between the two tells you how far away the epicenter is. In water there is another kind of wave, called a gravity wave, the kind you see at the beach. All of these wave require a medium. There is no sound in a vacuum.
The trombone is a wind musical instrument and as all musical instruments can produce a standing (or stationary) wave.
This kind of waves is the result of the composition of two waves that produces a pattern that looks like it is not moving but just vibrating. Some points of the wave look like they are not even vibrating, they just stand still, and they are called nodes. Other points of the wave vibrate from the maximum positive value to the maximum negative value and are called antinodes.
If you provided the aforementioned line 19, that would kinda be great.
