1. Transverse wave – A wave with a direction of propagation that is perpendicular to its direction of
oscillation
Longitudinal wave – A wave with a direction of propagation that is parallel to its direction of oscillation
Supersonic speed – Any speed that is faster than the speed of sound in the substance of interest
Sonic boom – The sound produced as a result of an object traveling at or above Mach 1
Pitch – An indication of how high or low a sound is, which is primarily determined by the frequency of
the sound wave
Frequency equals speed *v* divided by wavelength *that funny Greek letter at the bottom*.
(14.1)
You see them [the waves] because water heaves up and down. The crests and troughs that result from
such motion in the water produce visible waves. In physics terms, we say that water is the medium
through which the waves in the ocean travel.
Sound is a longitudinal wave.
The speed of sound in air is given by the following equation:
Sound waves with low pitch have low frequency.
Sound waves with high pitch have high frequency.

2. Waves with frequencies higher than 20,000 Hz are called ultrasonic waves, and waves with frequencies
below 20 Hz are called infrasonic waves.
The amplitude of a sound wave governs how loud the sound is.
Equations: