4.2.1. Rate of Change of Mass

Try these first

1. 1.

   What does the principle of mass conservation state?

   Hint

   Think about how matter behaves in physics.

2. 2.

   Define the continuity equation.

   Hint

   Consider how fluids flow in and out of a control volume.

3. 3.

   What does the mass conservation principle state?

   • Mass can be created
   • Mass can be destroyed
   • Mass cannot be created or destroyed

   Hint

   Consider basic laws of science about matter.

4. 4.

   The continuity equation in fluid dynamics is expressed as?

   • True
   • False

   Hint

   Think about the relationship between mass and fluid flow.

5. 5.

   Given a scenario where fluid enters a control volume at a specific rate but three outlets are present. Calculate the net mass flow rate and determine the divergence.

   Hint

   Start with the formula for mass flow rates at the inlets and outlets.

6. 6.

   A pipe system reduces in diameter. Explain how the continuity equation applies, and calculate the expected change in velocity if density remains constant.

   Hint

   Use the equation A1V1 = A2V2 to relate areas and velocities.