Control volume analysis concepts: Momentum flux is a result of fluid motion across the control surface. External forces, including surface forces and body forces act on a control volume. The resultant force on a control volume results from the interaction of the momentum fluxes, surfaces, and body forces. Multiple control volumes may be used within a problem. The conservation equations for a fluid are a system of equations. Begin by examining what is known and considering the control volume(s) needed. Carefully consider the control volume that would allow the determination of the velocity of the air