Buoyancy Experiment Calculator
Determine unknown densities using Archimedes' principle and floating object experiments
Buoyancy Experiment Setup
Ball Measurements
Diameter of the floating object
Mass of the floating object
Liquid Properties
Density of bottom liquid (e.g., saltwater: ~1159 kg/m³)
Cap Height Measurement
Height of the ball portion above the interface
Experiment Results
Force Analysis
Volume Distribution
Example: Golf Ball Experiment
Setup
Golf Ball: Diameter = 1.68 in, Mass = 1.62 oz
Bottom Liquid: 20% saltwater solution (ρ = 1159 kg/m³)
Top Liquid: Dish soap (unknown density)
Measurement: Cap height = 0.5 in
Result
Ball density: 1,129 kg/m³
Dish soap density: ~1,018 kg/m³
Force equilibrium: Weight = Bottom buoyancy + Top buoyancy
Materials Needed
Floating Object
Golf ball, ping pong ball, or any spherical object
Two Liquids
Different densities (e.g., saltwater and dish soap)
Measuring Tools
Ruler, scale, measuring cup
Container
Clear glass or plastic vessel
Common Densities
Experiment Tips
Pour liquids slowly to avoid mixing
Use clear containers to see the interface
Measure the ball precisely for accurate results
Higher salinity creates denser saltwater
Understanding Buoyancy Experiments
Archimedes' Principle
Any object immersed in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object. This fundamental principle allows us to determine unknown densities through careful measurement.
Force Equilibrium
When an object floats between two liquids, the total upward buoyant force equals the object's weight. This creates the equation: mg = ρ₁V₁g + ρ₂V₂g, where each liquid contributes based on the volume it displaces.
Buoyant Force Formula
FB = ρ × V × g
- FB: Buoyant force (N)
- ρ: Fluid density (kg/m³)
- V: Displaced volume (m³)
- g: Gravitational acceleration (9.81 m/s²)
Experimental Procedure
- 1.Measure the ball's diameter and mass accurately
- 2.Prepare saltwater with known concentration
- 3.Pour saltwater into the container
- 4.Place the ball and slowly add the unknown liquid
- 5.Measure the height of the ball cap above the interface
- 6.Calculate the unknown density using this calculator
Spherical Cap Volume
V = πh²(3r - h)/3
- V: Cap volume (m³)
- h: Cap height (m)
- r: Sphere radius (m)