The acoustic wave equation (and the mass and momentum balance equations) are often expressed in terms of a scalar potential φ {\displaystyle \varphi } where u = ∇ φ {\displaystyle \mathbf {u} =\nabla \varphi } .
Persamaan gelombang akustik (dan persamaan massa dan momentum keseimbangan) sering dinyatakan dalam skalar potensial φ {\displaystyle \varphi } di mana u = ∇ φ {\displaystyle \mathbf {u} =\nabla \varphi } .