The intensity of a progressive wave is defined as the average power transmitted through a surface per unit area.
Show that the SI base units of intensity are 
.
The intensity 
of a sound wave is related to the amplitude 
of the wave by:
where:
is the density of the medium through which the sound is passing,
is the speed of the sound wave,
is the frequency of the sound wave, and
is a constant.
Show that has no units.
Calculate the intensity, in 
, of a sound wave where:
= 20,
= 1.2 in SI base units,
= 330 in SI base units,
= 260 in SI base units and
= 
.
.
