We will be considering the parts of a wave with the wave represented as a transverse wave as in the following diagram:
In the above diagram the white line represents the position of the medium when no wave is present. This medium could be imagined as
We will be considering the parts of a wave with the wave represented as a transverse wave as in the following diagram:
In the above diagram the white line represents the position of the medium when no wave is present. This medium could be imagined as a rope fixed at one end a few feet above the ground and held by you at the other end.
The yellow line represents the position of the medium as a wave travels through it. We simply say that the yellow line is the wave. If we consider the rope mentioned before, this wave could be created by vertically shaking the end of the rope.
Often, when several waves are traveling along a medium as shown above, the continuous group of waves is called a wave train. And, since the waves are made again and again, with each wave requiring the same amount of time for its creation, we say that the wave is periodic.
The section of the wave that rises above the undisturbed position is called the crest. That section which lies below the undisturbed position is called the trough. These sections are labeled in the following diagram:
The term amplitude can have slightly different meanings depending upon the context of the situation.
Its most general definition is that the amplitude is the maximum positive displacement from the undisturbed position of the medium to the top of a crest. This is shown in the following diagram:
In some discussions it is important to distinguish between positive and negative amplitudes. These displacements are shown in the following diagram:
Sometimes it is necessary to discuss an 