Properties of Waves

Transverse Waves

The direction of wave is perpendicular to the action creating the wave.

eg. Electromagnetic waves, Seismic S-Waves

Longitudinal Waves

Series of compressions and rarefactions

The direction of the wave is parallel to the action creating it

eg. sound waves, Seismic P Waves

The Period of a Wave (T)

Amount of time (t) taken for one wave to occur

T=t/N (N = no. total cycles)

Frequency of a Wave (f)

NO. cycles in a period of time

f= N/t (no. total cycles)

Unit: 1/s or Hz

Wavelength (λ)

The length of one complete cycle

Unit (m)

The amplitude of a wave (A)

Max disturbance of the wave from equilibrium

* amount of energy carried is related to amplitude
* high energy → high amplitude
* low energy → low amplitude
* energy change does not effect wavelength, frequency, or speed of pulse, but it does effect amplitude

frequency and period relationship

f=1/T

T=1/f

Wavelength and Speed Equations

v=λf

c=λf

c= △d/ △t

Mechanical Wave

a wave that cannot transmit its energy through a vacuum

eg. sound

Propagation

the process by which a disturbance such as the motion of electromagnetic or sound waves

The Doppler Effect

the change in frequency of waves produced by a moving source with respect to the observer

* when object producing sound is moving towards the observer the waves bunch up in the direction of motion: increased frequency / higher pitched
* object moving towards observer: use (-)
* when object producing sound is moving away from the observer the waves spread out in the direction of motion: decreased frequency / lower pitched
* object moving away from observer: use (+)