## Summary of Wave Properties

Waves is a broad term. All waves however have several things in common:

• They all involve transport of energy. Sometimes this transport is localized, as when a standing wave is formed.

• They do so without net motion of the medium through which they pass. The waves move, but the medium through which the wave passes only oscillates.

• They all involve vibrations of some sort.

• Waves may be continuous, with a succession of individual oscillations, as opposed to a wave pulse which involves just a few oscillations.

There are two different categories of waves – transverse and longitudinal. Transverse waves have the property that the vibrations of the wave are perpendicular to the direction of travel of the wave, while longitudinal waves have the property that the vibrations are parallel to the direction of travel of the wave. Some examples are given in the table.

 Wave Mode of Energy Transfer Water Waves (Transverse) Up and down motion of the water. Sound Waves (Longitudinal) Vibrational Energy is given to the air and to anything impacted by the wave. Light Waves (Transverse) The light excites electrons in atoms or gives kinetic energy to electrons in metals or gas atoms when it is absorbed. Earthquake Waves (Transverse) Causes the Earth's surface to move up and down. Earthquake Waves (Longitudinal) Causes the Earth's surface to move back and forth. Waves on a String (Transverse) Kinetic or vibrational energy of the string and elastic energy as the string is stretched. Compression Waves (Longitudinal) Kinetic or vibrational energy of the medium and elastic energy as the medium is compressed and stretched.

In addition, both transverse and longitudinal waves can be subdivided into travelling waves, which transport energy from place to place, and standing waves, in which the wave is confined, so the vibrations occur in a confined space and restrictions are placed upon the oscillations.