How are pressure wave crests and troughs related to longitudinal wave?
Since this is not my area of expertise, I searched Google under the key words "wave crests troughs longitudinal wave" to get these possible sources:
http://www.google.com/search?client=safari&rls=en&q=wave+crests+troughs+longitudinal+wave&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
Pressure wave crests and troughs are directly related to longitudinal waves. To understand this relationship, let me explain what longitudinal waves are:
Longitudinal waves are a type of wave in which the particles of the medium vibrate parallel to the direction of wave propagation. In simpler terms, as the wave moves through a medium, the particles of the medium oscillate back and forth in the same direction as the wave itself.
Now, let's focus on pressure wave crests and troughs:
1. Pressure Wave Crest: In a longitudinal wave, when a particle in the medium is at its maximum displacement or maximum compression, it is considered a pressure wave crest. At this point, the particles are closer together, resulting in higher pressure.
2. Pressure Wave Trough: On the other hand, when a particle in the medium is at its maximum displacement or maximum rarefaction (spreading out), it is termed a pressure wave trough. At this point, the particles are farther apart, resulting in lower pressure.
So, in summary, as a longitudinal wave propagates through a medium, it creates regions of compression (crests) and rarefaction (troughs), which correspond to higher and lower pressure areas, respectively. These pressure variations are the direct result of the oscillatory motion of the particles in the medium along the same direction as the wave propagation.