4.3.2. Implications of Mass Conservation

Try these first

1. 1.

   What is the principle of mass conservation?

   Hint

   Think about how we can balance mass in a system.

2. 2.

   Define the continuity equation.

   Hint

   How do you relate inflow and outflow of mass?

3. 3.

   What does the continuity equation express?

   • A. Mass can be created.
   • B. Mass must balance input and output.
   • C. Mass can be destroyed.
   • D. Mass remains unchanged.

   Hint

   What principle governs the flow in closed systems?

4. 4.

   True or False: The divergence of mass flux is always zero in compressible flow.

   • True
   • False

   Hint

   Consider how compressible flow behaves in terms of density changes.

5. 5.

   A fluid flows through a pipe that begins with a known density and velocity. If the diameter decreases, calculate the new velocity using mass conservation principles.

   Hint

   Use the relation of area and velocity for fluids.

6. 6.

   Describe how mass conservation principles can be utilized in designing a water distribution system.

   Hint

   Consider the implications of pressure and flow rate in your design.