2.7. Steady Control Volume Form of Newton’s Second Law

Try these first

1. 1.

   What is the Reynolds Transport Theorem used for?

   Hint

   Think about how we can look at fluids moving across boundaries.

2. 2.

   Define the Continuity Equation.

   Hint

   Consider inflow and outflow in a pipe.

3. 3.

   What does the Continuity Equation ensure in fluid flow?

   • Mass flow rate is constant
   • Mass inflow is greater than outflow
   • Velocity is constant

   Hint

   Think about how fluids behave in pipes.

4. 4.

   True or False: The momentum equation applies only to fluids at rest.

   • True
   • False

   Hint

   Consider where momentum comes into play.

5. 5.

   A pipe has a diameter of 0.5 m at inlet and 0.3 m at outlet. Water flows at 3 m/s at the inlet. Calculate the velocity at the outlet.

   Hint

   Make sure to keep units consistent!

6. 6.

   A water jet strikes a flat plate with a mass flow rate of 2 kg/s and exits perpendicular to the plate. If the plate experiences no horizontal motion, calculate the force exerted on the plate.

   Hint

   Use the change in momentum to find the force.