All Flashcards
What happens when the buoyant force equals the weight of an object?
The object floats or is in equilibrium within the fluid.
What happens when the weight of an object is greater than the buoyant force?
The object sinks.
What happens when an object reaches terminal velocity?
The net force on the object is zero, and its velocity becomes constant.
What is the effect of increasing an object's velocity in a fluid?
The resistive force (drag force) increases.
What is the effect of a non-zero net force on an object according to Newton's Second Law?
The object accelerates in the direction of the net force (ΣF = ma).
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).
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)