Waves

Waves

1. Transverse

   • Vibrate at right angels to the direction the enerigy is moving.

2. Longitudinal

   • Vibrate back and forth in the same direction the energy is moving.

3. Wave types

   • Mechanical Waves: Require a medium to travel through. e.g Sound wave travel through air at 340.29 m s
   • Electromagnetic Waves: Do not require a medium to travel through. They travel through air vacuum at 299 792 458 m/s.They travel through other mediums at a slower speed e.g glass 250 000 0000m/s.

4. Wave Properties

   • Wavelength = the distance from one crest to the next. (or from one trough to the next, or from one compression to the next) The S.I. unit is the metre (m).The Greek letter “lambda” λ is used as a symbol for wavelength.
   • Amplatiude
   • Frequency (f) = the rate at which the wave is vibrating. The number of waves that pass a given point in 1 second, or the number of complete vibrations per second. S.I. unit is the “hertz” (Hz) 1 Hz = 1 wave/sec.
   • Velocity (v) = the speed of the wave, in metres/sec.(ms-1) There is a simple relationship between Velocity, Wavelength and Frequency:
   • Period (T) = the time (in seconds) for one completevibration to occur. Note that there is a simple relationship between Frequency and Period... they are reciprocals.
   • (a or A) = the distance that a particle in the medium is displaced from its “rest position” at a crest or trough. i.e. the maximum displacement distance.