Physical Interpretation of the Net Rate of Mass Outflow
Following Eqn. (5.24), the divergence term in Eqn. (5.47) can be expanded to yield:
\nabla \cdot c \mathbf{v}=c \nabla \cdot \mathbf{v}+\mathbf{v} \cdot \nabla c (5.24)
\frac{\partial \rho}{\partial t}+\nabla \cdot \rho \mathbf{v}=0 (5.47)
\underbrace{\nabla \cdot \rho \mathbf{v}}_{1}=\underbrace{\rho \nabla \cdot \mathbf{v}}_{2}+\underbrace{\mathbf{v} \cdot \nabla \rho}_{3} . (E5.6.1)
Give the physical significance of each of the three numbered terms in Eqn. (E5.6.1).
