3.1.1. Lecture - 14: Conservation of Momentum: Example Problems

Try these first

1. 1.

   Define conservation of momentum.

   Hint

   Think about how forces affect motion.

2. 2.

   What is a control volume in fluid mechanics?

   Hint

   Consider it as a box around fluid flow.

3. 3.

   What does conservation of momentum help us predict?

   • Temperature changes in fluids
   • Fluid motion and interaction
   • Fluid density variations

   Hint

   Think about what momentum affects.

4. 4.

   True or False: Steady flow indicates that all properties of a fluid in motion are changing over time.

   • True
   • False

   Hint

   Consider what 'steady' implies.

5. 5.

   A pipe has two exits. At the first exit, 5 m/s flows into a tank, while 10 m/s exits into another region. If the diameter at Exit 1 is 0.1 m and Exit 2 is 0.15 m, calculate the force acting on the pipe from these exits.

   Hint

   Utilize mass conservation equations alongside momentum flux principles.

6. 6.

   For aircraft refueling at 568 liters/min with a specific gravity of 0.68, calculate the thrust needed to keep a constant velocity. Determine the momentum before and after refueling.

   Hint

   Boyle's Law could assist in relating pressure changes to thrust requirements.