Answer
$P = \frac{0.4}{10}~cos[\frac{(2\pi) (10)}{4.9}- 1026~t]$
We can see a sketch of the graph in the window $[0,0.05]$ by $[-0.05, 0.05]$
The sound pressure $P$ at a distance of ten feet from the source oscillates continuously between $0.04$ and $-0.04$
Work Step by Step
$P = \frac{a}{r}~cos(\frac{2\pi r}{\lambda}- ct)$
$\lambda = 4.9~ft$
$c = 1026~ft/s$
$a = 0.4~lb/ft^2$
$r = 10~ft$
$P = \frac{0.4}{10}~cos[\frac{(2\pi) (10)}{4.9}- 1026~t]$
We can see a sketch of the graph in the window $[0,0.05]$ by $[-0.05, 0.05]$
The sound pressure $P$ at a distance of ten feet from the source oscillates continuously between $0.04$ and $-0.04$
