Answer:
Waves
Waves can be described as oscillations or vibrations about a rest position. For example:
sound waves cause air particles to vibrate back and forth;
ripples cause water particles to vibrate up and down.
The direction of these oscillations is the difference between longitudinal and transverse waves.
Longitudinal waves
A longitudinal wave is one in which the vibrations of the particles are parallel to the direction in which the energy of the wave travels.
Demonstrating longitudinal waves
Longitudinal waves show areas of compression and rarefaction:
compressions are regions of high pressure due to particles being close together.
rarefactions are regions of low pressure due to particles being spread further apart.
An accelerating electric charge will emit transverse electromagnetic waves. These waves are propagating away in wave fronts that become flatter and flatter as getting further from the source. So they will start to resemble a plane wave
