Short answer
Density shows how much mass is per unit volume. Two objects of the same size can have different masses and behave differently in water.
Density is important, not just mass
Density shows how much mass is per unit volume. Two objects of the same size can have different masses and behave differently in water.
In this model, the average density of an object is less than the density of water - it floats on the surface. If the density is higher, it sinks. At equal density, a completely submerged object can remain inside the water.
See it for yourself
Compare mass, volume and density. Test your prediction.
Open experiment ↗Try it on a model
Make the mass 100 g and the volume 200 cm³. Then reduce the volume to 50 cm³, maintaining the mass.
ρ = m / V
What is simplified in the model
The density of water is taken to be 1 g/cm³. The item does not absorb water; surface tension and air bubbles are not taken into account.
For adults · discuss together
The density of water is taken to be 1 g/cm³. The item does not absorb water; surface tension and air bubbles are not taken into account.
Before experience
Ask: “What do you think will happen?” Let the child check his guess first.
After the experience
What has changed? What remains the same? Where can you notice a similar phenomenon?
