18.2.3. Derivation of Conservation of Linear Momentum

Try these first

1. 1.

   Define the Reynolds transport theorem.

   Hint

   Think about how changes in the system relate to flow across its boundaries.

2. 2.

   What is the significance of assuming incompressible flow?

   Hint

   Consider how density impacts fluid dynamics.

3. 3.

   What is the main principle of the conservation of momentum?

   • Momentum must always increase
   • Momentum is conserved in the absence of external forces
   • Momentum can be lost

   Hint

   Think about systems where forces are applied or absent.

4. 4.

   Is laminar flow characterized by smooth streamlines?

   • True
   • False

   Hint

   Visualize how the layers of fluids move in comparison to turbulent flow.

5. 5.

   A fluid with a mass flow rate of 2 kg/s enters a pipe at a velocity of 3 m/s. Determine the momentum entering the pipe.

   Hint

   Use the straightforward formula for momentum.

6. 6.

   Derive the equation for momentum conservation in a fixed control volume where pressure and viscous forces are acting on it.

   Hint

   Think about interrelation of forces involved.