01. What is a wave?

LEARNING TARGETS

• Define the terms displacement, amplitude, frequency and period

• State that progressive (travelling) waves transfer energy.

• Describe the terms crest, trough, compression and rarefaction.

• Define the term wavelength

• Describe and give examples of transverse and of longitudinal waves.

• Apply the relationship between wave speed, wavelength and frequency.

The basic description of a wave is that is the transmission of energy from one place to another without the transfer of matter (or mass)

Every individual point on the wave is undergoing simple harmonic motion around its own rest position.

There are many different types of waves such as Light, Sound, Radio, X-rays, Infra-red, Seismic, Water, Ultraviolet, Ultra-sound, Waves on a string or slinky, Gamma rays and Microwaves.

We can put all of these waves into one of two groups based on the way in which vibrations occur within the wave. These two groups are called Transverse and Longitudinal waves.

Transverse waves: The vibrations occur at right angles (perpendicular) to the direction in which the wave transmits energy (click on the wave below to see how a transverse wave moves)

Longitudinal waves: The vibrations occur in the same plane (parallel) to the direction in which the wave transmits energy (click on the wave below to see how a longitudinal wave moves)