20.5.1. External Forces in Linear Momentum

Try these first

1. 1.

   What is linear momentum?

   Hint

   Think about the definition of momentum in physics.

2. 2.

   Define a control volume.

   Hint

   Consider how we isolate a system to analyze forces.

3. 3.

   What is the principle of linear momentum conservation?

   • Momentum can be created
   • Momentum is conserved unless acted upon by an external force
   • Momentum decreases over time

   Hint

   Think about how momentum behaves in an isolated system.

4. 4.

   True or False: Surface forces can include gravitational effects.

   • True
   • False

   Hint

   Consider the nature of the forces.

5. 5.

   Consider a cylindrical tank with inflow and outflow pipes. If the fluid enters the tank at a rate of 5 m³/s and exits at 4 m³/s, calculate the net momentum change in the control volume if the fluid density is 1000 kg/m³.

   Hint

   Focus on the flow rates and how they relate to momentum.

6. 6.

   Given a 3D flow simulation around a rectangular structure, determine the forces acting on the structure if the pressure distribution is non-uniform. Describe how you would set up your computational model.

   Hint

   Consider how pressure changes affect forces overall.