Wave motion
is initiated by an energetic disturbance that subsequently travels through a medium with a fixed velocity (for homogeneous media). This moving disturbance is referred to as a traveling wave.
A wave propagates through a medium via internal cohesive forces, though the medium itself is not transported.
A simple sinusoidal disturbance of frequency will produce periodic motion
with a wavelength given by
, where is the wave speed of propagation. The wavelength represents the distance between successive, periodic movements of a medium.
The wave speed is determined by the mass (or mass density) and elastic modulus (or tension) of the medium in which it travels. A more “massy” material will have a lower propagation speed. A “stiffer” material will have a higher speed of propagation.
Transverse Wave Motion: vibration of particles in the medium is perpendicular to the direction of wave motion.
Sound waves
are longitudinal disturbances that travel in a solid, liquid, or gas.
The speed of sound in air is approximately given by
(meters / second), where is the temperature of the air in degrees Celsius. A value of 345 meters / second is a good estimate at room temperature.