\begin{equation} p_{\, max} = G \, c \, A \qquad \textnormal{(Max pressure of sound wave, G = bulk modulus)} \end{equation} \begin{equation} v = \sqrt{ \frac{G}{\rho}} \qquad \textnormal{(Longitudinal wave in a fluid)} \end{equation} \begin{equation} v = \sqrt{ \frac{\beta \, R \, T}{M}} \qquad \textnormal{(Sound wave in ideal gas)} \end{equation} \begin{equation} v = \sqrt{ \frac{Y}{\rho}} \qquad \textnormal{(Longitudinal wave in solid rod)} \end{equation}
\begin{equation} I = \frac{1}{2} (\omega \, A)^2 \sqrt{\rho G} = \frac{p_{max}^2}{2 \, \rho \, v} = \frac{p_{max}^2}{2 \sqrt{\rho \, G}} \qquad \textnormal{(Intensity of sound wave)} \end{equation} \begin{equation} \phi = (10 \, dB) \, \textnormal{log} \frac{I}{I_0} \qquad \textnormal{(Sound intensity level)} \end{equation}
\begin{equation} f_n = \frac{n \, v}{2 \, L} \quad \textnormal{(n = 1, 2, 3, ...)} \qquad \textnormal{(2 open ended pipe)} \end{equation} \begin{equation} f_n = \frac{n \, v}{4 \, L} \quad \textnormal{(n = 1, 3, 5, ...)} \qquad \textnormal{(1 open ended pipe)} \end{equation}
When two waves come together, the resulting wave is a combination of the two individual waves. The resulting amplitude is the addition of the two individual amplitudes.
When the two amplitudes are both positive at a certain point, we call this constructive interference. When the two amplitudes are opposite each other, we call this destructive interference, and the resulting amplitude is 0.
\begin{equation} f_{beat} = f_b - f_a \end{equation}
\begin{equation} f_{obs} = \frac{v + v_{obs}}{v + v_{source}} \, f_{source} \end{equation}
\begin{equation} \textnormal{ sin } \psi = \frac{v}{v_{source}} \end{equation}
Next module Temperature, heat, first law of thermodynamics