About Density
Why do some materials like wood float in water, and others don’t? Interact with blocks of different materials, including a custom option by modifying their mass and volume, to explore the effect on the density and discover the conditions for sinking or floating in water. Play detective to determine the material of each block by comparing its density with the values in the table.
How to play Density
Everything is hands-on: drag, click and experiment — the simulation reacts instantly. Why do some materials like wood float in water, and others don’t?
Questions & answers
- What is Density?
- Density is a free interactive simulation from PhET Interactive Simulations (University of Colorado Boulder) that you can play right in your browser on crumble.lol — no downloads and no sign-up. Why do some materials like wood float in water, and others don’t? Interact with blocks of different materials, including a custom option by modifying their mass and volume, to explore the effect on the density and discover the conditions for sinking or floating in water.
- What can kids learn from Density?
- It helps kids explore: describe how the concept of density relates to an object's mass and volume. explain how objects of similar mass can have differing volume, and how objects of similar volume can have differing mass. explain why changing an object's mass or volume does not affect its density (ie, understand density as an intensive property). measure the volume of an object by observing the amount of fluid it displaces. identify an unknown material by calculating its density and comparing to a table of known densities.
- What age is Density good for?
- It is designed for elementary school (roughly ages 5–10) up to university, and curious kids outside that range can absolutely enjoy poking around it too.
- Is Density free to play?
- Yes — Density is completely free on crumble.lol and runs fully in your browser on computers and tablets.