All Flashcards
What are the steps to drawing an effective FBD?
- Identify the object. 2. List all forces. 3. Draw the object. 4. Draw force vectors. 5. Label vectors. 6. Add annotations. 7. Check for accuracy.
How do you relate FBDs to problem-solving?
- Always start with an FBD. 2. Relate FBDs to Newton's Laws (ΣF = ma). 3. Be consistent with directions.
How to derive the terminal velocity of an object sinking in a fluid using FBDs?
- Draw FBD showing Weight, Buoyant Force, and Resistive Force. 2. Apply ΣF = 0 at terminal velocity. 3. Express Buoyant Force in terms of fluid density and object volume. 4. Solve for terminal velocity (vt).
What is the process to analyze forces and motion using FBDs?
- Draw a clear and accurate FBD. 2. Apply Newton's Second Law (ΣF = ma). 3. Choose a positive direction and stick with it. 4. Solve for unknowns.
What is the first step to solving a fluid problem?
Always start with a clear and accurate Free-Body Diagram (FBD).
What is Weight (W or Fg)?
The force of gravity acting on an object. Always points downwards.
What is Buoyant Force (Fb)?
The upward force exerted by a fluid on an object. Crucial for understanding floating and sinking.
What is Normal Force (N)?
A contact force exerted by a surface on an object. Only present when an object is resting on a surface.
What is Resistive Force (Fr)?
A force that opposes motion through a fluid. Increases with the object's velocity; often called drag force.
Define Free-Body Diagram (FBD).
A visual representation of all forces acting on an object.
Label the forces on an object floating in water.
1: Weight (W) downwards, 2: Buoyant Force (Fb) upwards.
Label the forces on an object sinking in water.
1: Weight (W) downwards, 2: Buoyant Force (Fb) upwards, 3: Resistive Force (Fr) upwards.
Label the forces on an object sunk to the bottom of a container.
1: Weight (W) downwards, 2: Buoyant Force (Fb) upwards, 3: Normal Force (N) upwards.
In a free-body diagram, which force always points downwards?
Weight (W or Fg)
What force is missing if an object is resting on the bottom of a container filled with fluid, but only Weight and Buoyant force are drawn on the FBD?
Normal Force (N)