compression
Fug
Compression is the part of a longitudinal wave where the particles of the medium are crowded together. Rarefaction is the part where the particles are spread apart.
This type of wave is called longitudinal waves.
boils clustered together are called carbuncles
a wave in which matter is moved back and forth in the direction the wave is moving
It is called a compression.
Since the particles of the medium vibrate parallel (length wise) to the direction of propagation of the energy. HEnce the name longitudinal.
Assuming that you are referring to longitudinal waves, the area where particles are closest together would be called the "compression" area. The "rarefaction" is the opposite; this is where the medium is least dense. Sound is a good example of longitudinal waves. If you look closely at a speaker cone, you be able to see that they seem to move in and out very rapidly. This is what "pushes" and "pulls" the air molecules and creates compressions and rarefactions which our ears receive and transmit as a neural impulse to our brain, allowing us to hear. Although transverse and longitudinal waves are both different types of waves, they are dissimilar (particles in a transverse wave move perpendicular to the motion of the wave (up and down) where as particles in a longitudinal wave move in the direction the wave is traveling).
Longitudinal. An example of a longitudinal wave is sound. It pushes the medium particles forwards and backwards, parallel to the wave's direction. Transverse waves cause particles to move perpendicular to the wave. (E.g. visible light, x-rays, microwaves)
If the particles of the medium vibrate in the direction of propagation of wave, as in sound waves that's why sound waves are called longitudinal waves.
its not a refraction its rarefaction
Motor neurons.
That is called a Longitudinal wave