2.4. Continuity Equation

Try these first

1. 1.

   What is the continuity equation in terms of flow rates?

   Hint

   Think about the relation between cross-sectional area and fluid velocity.

2. 2.

   Define a control volume.

   Hint

   Consider it as an imaginary box through which fluid flows.

3. 3.

   What does the continuity equation primarily express?

   • Conservation of energy
   • Conservation of mass
   • Newton's law

   Hint

   Consider which law correlates with mass in fluids.

4. 4.

   The mass flow rate must be constant in a flow system. True or False?

   • True
   • False

   Hint

   Recall the principle of conservation.

5. 5.

   A tank has a rectangular cross-section of 2m by 3m. Water flows out at a rate of 0.5 cubic meters per minute. If the water level is dropping, find the rate of drop in height.

   Hint

   Convert your flow rate to match the units of height.

6. 6.

   Two pipes are connected: the first with a diameter of 10 cm and the second with 15 cm. If the velocity in the first pipe is 3 m/s, find the velocity in the second pipe.

   Hint

   Remember to find A using the diameter to calculate areas.