Steel Sphere Density Comparison Kit


【Product Description】

Pair of two shiny steel spheres with the same mass but with significantly different diameters, thus making their densities vastly different to each other.

【Overall Advantages to Users】

Students generally prone to predict that the larger steel sphere has more likelihood to sink in water than a smaller one does. However, contrary to their expectations, the large one floats in water, while the small one alone sinks. They, then, will likely notice, through their own enlightening hands-on experience, the scientific concept of buoyancy that is the ability to float after relating the sphere’s mass to its volume and realizing the two spheres have quite different densities to be represented by each sphere’s mass per its unit volume.


  • Archimedes’ principle
  • Buoyant force
  • Displacement volume
  • Water pressure
  • Density



【To students】

Suitable for an introductory icebreaking at the beginning of the topic on properties of matter allowing teachers to give very minimal instruction.

  • Large steel sphere:
    x1 pcs, Size: φ127mm, Weight: 115g
  • Small steel sphere
    x1 pc, Size: φ35mm, Weight: 115g