3.3. Example Problems

Try these first

1. 1.

   What is steady flow in fluid mechanics?

   Hint

   Think about how changes in velocity would affect flow characteristics.

2. 2.

   Define a control volume.

   Hint

   Consider why we isolate a region to understand fluid behavior.

3. 3.

   What does the conservation of momentum state?

   • Momentum is always increasing
   • Total momentum remains constant
   • Momentum can be created or destroyed

   Hint

   Think about how momentum behaves in a closed system.

4. 4.

   True or False: Steady flow means that the fluid's pressure and velocity are constant over time.

   • True
   • False

   Hint

   Focus on what 'steady' means in terms of time dependence.

5. 5.

   A 2000 kg truck is moving at 20 m/s. It encounters a sudden obstacle causing a change in momentum due to an emergency stop. Calculate the required stopping force if it takes 5 seconds to stop.

   Hint

   Remember that force relates to the rate of change of momentum.

6. 6.

   A water tank has two exits with different velocities, flowing out. How would you calculate the net force acting on the tank due to these exits?

   Hint

   Consider that pressure at the exits might affect your calculations.