Wave Definitions

• Elastic Medium

A medium that allows for the transfer of waves by acting as if it were an array of particles connected by springs with each particle having an equilibrium or rest position.

• Disturbance

A build up of energy in a system which allows for the propagation of a wave.

Pulse

• A single non-repeated disturbance.

Crest and Trough

• A crest is region of upward displacement in a transverse wave.

• A trough is an area of downward displacement in a transverse wave.

Compression and Rarefaction

• A compression is the area of a longitudinal wave where the particles are closer together than the equilibrium position.

• A rarefaction is the area of a longitudinal wave where the particles are farther apart than the equilibrium position.

Phase

• Phase is used to describe the position and direction of motion of a particle on a wave.

• Two particles are in-phase if they have the same displacement and are moving in the same direction.

• Two particles have opposite phase if they have opposite displacements and are moving in opposite directions.

Wavelength

• Wavelength is the distance between any two consecutive points on a wave that are in-phase.

• The example to the left is only for transverse waves.

Frequency and Period

• Frequency is the number of oscillation or waves that occur per unit time.

• Period is the amount of time that passes as one complete wave passes a given point.

Speed

• Speed is the time rate of motion for a wave.

Speed = Wavelength • Frequency

Amplitude

• Amplitude is the maximum displacement in the y direction.

• The amplitude of a wave is an indication of the wave’s energy.