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Surface Area & Volume Relationships: Sphere, Cone, and Cylinder

Experiment video

What you will learn

Verify Archimedes' ratio of volumes and surface areas between a cone, a sphere, and a cylinder having identical radius (r) and height (h = 2r) using dry fine sand displacement.

Materials needed

  • Hollow transparent acrylic geometric models: Cylinder (radius r = 5 cm, height h = 10 cm), Sphere (radius r = 5 cm with top aperture), Cone (radius r = 5 cm, height h = 10 cm) set
    Hollow transparent acrylic geometric models: Cylinder (radius r = 5 cm, height h = 10 cm), Sphere (radius r = 5 cm with top aperture), Cone (radius r = 5 cm, height h = 10 cm) set
    ₹50
    What is it?

    Set of hollow transparent acrylic geometric solids sharing identical radius r = 50 mm and height h = 100 mm.

    Specifications
    Solids Included
    Right circular cone, cylinder, full sphere, hemisphere
    Wall Thickness
    2.5 mm optical clear acrylic
    Lid Openings
    Removable fill caps on all bases
    Calibration
    Exact 1:2:3 volumetric ratio matched
  • Fine dry colored sand or water kg
    NS
    Fine dry colored sand or water kg
    ₹95
    What is it?

    Fine dry quartz test sand (graded mesh 50-70) colored with non-toxic pigment.

    Specifications
    Particle Size
    0.2 – 0.3 mm uniform quartz grains
    Flowability
    Free-flowing dry granular bulk density 1.55 g/cm³
    Quantity
    2.0 kg in plastic pour container
  • Measuring Flask (1000 mL)
    Measuring Flask (1000 mL)
    ₹140
    What is it?

    Graduated 1000 mL Class A measuring cylinder for volumetric liquid cross-check.

    Specifications
    Capacity
    1000 mL
    Graduation
    10 mL subdivisions
    Material
    Polypropylene chemical/shatter resistant
  • Plastic funnel and collection tray
    Plastic funnel and collection tray
    ₹185
    What is it?

    Standard laboratory apparatus used in Surface Area & Volume Relationships: Sphere, Cone, and Cylinder.

    Specifications
    Category
    Mathematics Apparatus
    Grade
    CBSE / NEP 2020 Laboratory Standard
  • Leveling straightedge ruler
    Leveling straightedge ruler
    ₹230
    What is it?

    Standard laboratory apparatus used in Surface Area & Volume Relationships: Sphere, Cone, and Cylinder.

    Specifications
    Category
    Mathematics Apparatus
    Grade
    CBSE / NEP 2020 Laboratory Standard

Tick items as you collect them. Tap + to see the product, specifications and buy options.

Stay safe

  • Ensure sand is completely dry and free of clumps to ensure uniform packing density.
  • Always level the sand rim with a flat straightedge; avoid packing or shaking vigorously between fills.
  • Pour sand through a funnel slowly into the models to avoid spilling outside the measurement rim.
  • Wipe acrylic models with anti-static cloth to prevent sand grains sticking to walls.

Steps

0 of 7 steps done
  • 1Verify dimensions of acrylic solids: cylinder height h = 10 cm, radius r = 5 cm; cone height h = 10 cm, radius r = 5 cm; sphere diameter 2r = 10 cm.
    Observation

    Inspect hollow transparent plastic shapes: cone, hemisphere, sphere, and cylinder sharing identical radius r = 5.0 cm and height h = 10.0 cm.

    Safety

    Check plastic shapes for cracks or leaks before filling with liquid/sand.

  • 2Fill the hollow cone completely with fine sand and level off flush with the rim using a straightedge.
    Observation

    Fill hollow cone to the brim with fine colored dry sand; level top surface with a straight ruler edge.

    Safety

    Pour sand over plastic tray to catch any spills.

  • 3Pour the sand from the cone into the empty cylinder. Observe that it fills exactly 1/3 of the cylinder's volume.
    Observation

    Pour sand from cone into cylinder: exactly one-third of cylinder is filled.

    Safety

    Tap cylinder base lightly to settle sand evenly.

  • 4Fill the cone two more times into the cylinder: three full cones exactly fill the cylinder (V_cylinder = 3 × V_cone = 3 × (1/3 πr²h) = πr²h).
    Observation

    Pour second full cone of sand into cylinder: cylinder is now two-thirds full.

    Safety

    Ensure cone is filled completely flush with brim each time.

  • 5Now empty the cylinder. Fill the hollow sphere model with fine sand.
    Observation

    Pour third cone of sand into cylinder: sand reaches the absolute brim of the cylinder, proving V(Cylinder) = 3 × V(Cone).

    Safety

    Zero sand remains left over; cylinder is filled to 100% capacity.

  • 6Pour the sphere's sand into the empty cylinder: it fills exactly 2/3 of the cylinder (V_sphere = 2/3 V_cylinder = 4/3 πr³).
    Observation

    Fill hollow sphere with 2 full measures of the cone, proving V(Sphere) = 2/3 V(Cylinder) = 4/3 πr³.

    Safety

    Return dry sand to storage hopper and wipe transparent models with microfiber cloth.

  • 7Combine one full cone of sand and one full sphere of sand: together they fill the cylinder 100% full.

Tap + on a step to see what you will observe and any safety tips.

Record your observations

Geometric Solid BodyTheoretical Formula (h = 2r = 10 cm)Volume Calculated (cm³)Sand Filling Measure (Scoops)Volume Ratio to Cylinder
Cone (r = 5 cm, h = 10 cm)V = 1/3 · π · r² · h = 1/3 × π × 25 × 10261.80 cm³1 scoop (Base unit 1.0)1 / 3 (33.3% of cylinder)
Sphere (r = 5 cm, d = 10 cm)V = 4/3 · π · r³ = 4/3 × π × 125523.60 cm³2 scoops (Exactly 2× cone)2 / 3 (66.7% of cylinder)
Cylinder (r = 5 cm, h = 10 cm)V = π · r² · h = π × 25 × 10785.40 cm³3 scoops (Exactly 3× cone)3 / 3 (100% full capacity)

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Result and conclusion

Empirically verified that Volume of Cone : Volume of Sphere : Volume of Cylinder = 1 : 2 : 3. Sand from one cone and one sphere exactly fills the circumscribed cylinder without spill.

V(Cone) : V(Sphere) : V(Cylinder) = (1/3 · πr²h) : (4/3 · πr³) : (πr²h) = 1 : 2 : 3 (for h = 2r)
ObservationWhat it means
Archimedes Epitaph Ratio 1:2:3Archimedes regarded this discovery as his crowning triumph: for a cylinder circumscribed around a sphere and cone (h = 2r), their volumes are strictly 1 : 2 : 3.
Experimental Volumetric ProofExactly 3 full measures of the cone fill the cylinder to the brim (V_cyl = 3 · V_cone).
Sphere to Cone EquivalencePouring 2 full measures of the cone fills the hollow sphere completely (V_sphere = 2 · V_cone = 4/3 πr³).
Surface Area RelationshipTotal surface area of sphere (4πr²) equals the curved surface area of the circumscribed cylinder (2πr·h = 2πr·2r = 4πr²).
Volumetric Relationship: Cone vs Sphere vs Circumscribed Cylinder02264526779030Empty Baseline261.8Right Circular Cone523.6Sphere (Hollow)785.4Cylinder (Circumscribed)Geometric Solid TypeVolume (cm³)

Sample readings. Replace with your own results.

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