Buoyancy & Archimedes Principle

WHAT IS BUOYANCY?

Buoyancy is the upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. Archimedes' Principle states that the buoyant force () is exactly equal to the weight of the fluid displaced by the object. This principle explains why heavy steel ships float while small pebbles sink.

THE CORE FORMULA

F_B = \rho_{fluid} V_{displaced} g\n\nWhere:\n- is the buoyant force (N)\n- is the density of the fluid (kg/m³)\n- is the volume of fluid pushed aside by the object (m³)\n- is 9.8 m/s²

HOW TO USE THIS VISUALIZATION

1. **Select Object**: Choose from different materials with varying densities.\n2. **Submerge the Object**: Drag the object into the fluid and observe the water level rise.\n3. **Watch the Forces**: Compare the Gravity () and Buoyancy () vectors.\n4. **Change Fluid**: Switch between water, oil, and honey to see how fluid density affects the force.

TRY THIS

1. Pick an object that sinks. Notice that even while sinking, there is still a buoyant force acting upward.\n2. Pick a floating object. Observe that in equilibrium, exactly equals .\n3. Completely submerge a floating object and release it. Watch the acceleration as .

CORE FORMULAS

AP EXAM CONNECTION

KEY TAKEAWAYS

• Buoyancy equals weight of displaced fluid.
• Floating objects: .
• Density determines if an object sinks or floats.
• Apparent weight is actual weight minus buoyant force.

PRACTICE QUESTIONS