Momentum Balance for Fluid Control Volumes

Linear momentum balance for a fluid control volume links Newton’s second law to moving fluid. The law says that the rate of change of linear momentum equals the sum of the external forces acting on the system. In a fluid system, this idea helps explain how motion and force are related.

A control ...

Newton's second law for a fluid system states that the rate of change of linear momentum in a flow with respect to time is equal to the sum of the external forces the system experiences.

At any given instant, when a control volume coincides with the fluid system, the forces acting on the system and those acting on the control volume's con...