Wave An oscillation that transfers energy and momentum.
Mechanical wave A disturbance of matter that travels along a medium. Examples include waves on a string, sound, and water waves.
Wave speed Speed at which the wave disturbance moves. Depends only on the properties of the medium. Also called the propagation speed.
Transverse wave Oscillations where particles are displaced perpendicular to the wave direction.
Longitudinal wave Oscillations where particles are displaced parallel to the wave direction.
In a transverse wave, perpendicular to the direction the wave travels, the particles are displaced. Examples of transverse waves include on a string vibrations and on the water surface ripples. By moving the slinky up and down vertically, we can create a horizontal transverse wave.
In a longitudinal wave, parallel to the direction the wave travels, the particles are displaced. Compressions that move along a slinky are an example of longitudinal waves. By pushing and pulling the slinky horizontally, we can make a horizontal longitudinal wave.
Common mistakes and misconceptions
Sometimes people forget that wave velocity is not the same as the velocity of the medium particles. How fast the disturbance travels through a medium is the wave speed. The velocity of the particle is how fast a particle moves about its position of equilibrium.
