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Buoyancy & Archimedes Lab — Cube in a Beaker

A solid cube of adjustable volume and density is lowered into a beaker of fluid. Hang it from a spring scale to read its apparent weight at any submerged fraction, or release it and watch it float or sink. Archimedes: F_b = ρ_fluid V_sub g. g = 9.81 m/s².

Mode

Spring scale

Submerged fraction %

The cube is lowered until this fraction of its height is under the surface. The scale reads the apparent weight W − F_b. If F_b exceeds W the string goes slack and the scale reads 0 — the cube would float at that depth.

Object

Volume V L Density ρ_obj kg/m³

Cube side s = V^1/3; mass m = ρ_obj V. Presets (kg/m³): Ice 917 · Wood (pine) 500 · Aluminum 2700 · Steel 7850.

Fluid & beaker

Fluid density ρ_fluid kg/m³ Beaker area A cm²

Presets (kg/m³): Water 1000 · Seawater 1025 · Vegetable oil 920 · Glycerin 1260.

Base fluid depth h₀ = 20 cm. Level rise Δh = V_sub / A_eff, where A_eff = max(A, 1.25 s²) so the cube always leaves a gap for the fluid; when s² ≥ 0.9 A the status warns that the object nearly fills the beaker.

Simulation

Sim speed ×

The cube is released from rest with its bottom 5 cm above the original surface. Motion: m a = −W + F_b − c v with drag c = 6 m (kg/s) so it settles quickly. If it reaches the bottom it comes to rest there.

static

Object

Mass0.000kg

Weight W0.000N

Volume0.00L

Side s0.00cm

Density0kg/m³

fits the beaker

Submersion

Depth d0.00cm

Fraction0.0%

V_sub0.000L

F_b0.000N

Displaced m0.000kg

Level rise0.00cm

A_eff0cm²

Scale & motion

Scale0.000N

F_net—N

v—m/s

y (bottom)0.00cm

ready

Prediction

Fraction0.0%

d_eq0.00cm

F_b,max0.000N

floats

Scale reading vs submerged fraction

Buoyant force vs V_sub

Scale reading vs submerged fraction

Buoyant force vs Vsub

Data table

Buoyant force vs V_sub