16.2.3. Conservation of Mass and Energy Equations

Try these first

1. 1.

   What is the conservation of mass?

   Hint

   Think about the flow in and out of a system.

2. 2.

   What is specific energy?

   Hint

   Recall the formula involving flow depth and velocity.

3. 3.

   What is the primary concept of the conservation of mass?

   • Mass can be created
   • Mass flows incompressibly
   • Mass inflow equals outflow

   Hint

   Think about a water tank—what goes in must come out.

4. 4.

   True or False: The specific energy is independent of flow depth.

   • True
   • False

   Hint

   Recall the specific energy formula.

5. 5.

   A channel has a flow depth of 2 meters and a velocity of 4 m/s. Calculate the specific energy.

   Hint

   Use the formula for specific energy carefully.

6. 6.

   Design a rectangular channel, noting the minimum perimeter for given flow conditions.

   Hint

   What is the relationship between width and depth?