What are waves?

• A wave is a disturbance that transfers energy from one place to another

• Waves transfer energy but they do NOT transfer matter

Ways to transfer energy

• As a Transverse wave - particles of the medium move perpendicular to the direction of the energy of the wave

• As a Longitudinal wave - particles move in the same direction as the energy of the wave

• As a surface wave - a combination of a transverse and longitudinal wave

Types of waves

• Mechanical - Waves that disturb matter require a medium

• Electromagnetic - Waves that disturb an electric and magnetic field. They do NOT require a medium to transfer energy. All EM waves travel at light speed (186,000 meters per second) in a vacuum.

Properties of waves

• Crest

• Trough

• Wavelength

• Amplitude

• Frequency

• Wave period

• Wave speed

Crest

The highest point of a wave

Trough

The lowest point of a wave

Wavelength

The distance over which the wave repeats. This is measured by the distance from one point on a wave to the next identical point later in the wave.

Amplitude

A measure of how far particles in the medium move away from their normal rest position.

Frequency

How many cycles of a wave occur in a given amount of time.  This property is measured in a unit of measurement called hertz (Hz), with one hertz (1Hz) being equal to one cycle per second.

Amplitude & Frequency in Sound Waves

When it comes to sound waves, humans detect a change in amplitude as a change in volume. Changes in frequency are detected as a change in the pitch of the sound.

Amplitude & Frequency in Light waves

With light waves, a change of frequency is seen as a change in color. A difference in amplitude is detected as a change in the brightness of the color of the wave.

Wave Period

This is the amount of time it takes for one wavelength or wave cycle to pass.

Wave speed

The speed at which a wave travels, called wave speed, depends on the properties of the medium. To calculate wave speed, you would multiply the frequency of the wave by its wavelength. The speed of waves depend on many factors, among them are the state of matter of the substance and the density of the substance.