Two Examples on Application of Continuity Equation in Fluid Mechanics

The continuity equation is a fundamental principle in physics that expresses the conservation of mass in a fluid or gas. It states that the rate of change of mass within a control volume must be equal to the net rate of mass flow into or out of the volume.
This equation can be interpreted to mean that the change in the amount of fluid within a given volume is due to the net flow of fluid into or out of that volume. In other words, if fluid is flowing into a volume faster than it is flowing out, the amount of fluid within that volume will increase over time, and vice versa.
The continuity equation is used in a variety of fields, including fluid mechanics, electromagnetism, and thermodynamics, to describe the behavior of fluids and other materials. It is a powerful tool for understanding the movement and behavior of fluids, and is often used in conjunction with other equations to model complex systems.