Density Tower
Loading simulation…
flagWhat you'll discover
- arrow_forwardExplain what density means using grams per millilitre
- arrow_forwardPredict the order of liquid layers before pouring
- arrow_forwardShow that pouring order does not change the final tower
- arrow_forwardPredict which layer an object will float on from its density
What is density?
Density tells you how much stuff is squeezed into a space. Imagine two identical spoons: one full of honey, one full of alcohol. The honey spoon is heavier because honey packs more material into the same space.
We measure density in grams per millilitre (g/mL). Honey is about 1.42 g/mL, water is exactly 1.00, and alcohol is only about 0.79. The bigger the number, the heavier each spoonful.
Liquids sort themselves
Pour several liquids into one glass and something magical happens: they line up by density, all by themselves! The densest liquid (honey, 1.42) pushes its way to the bottom, and the lightest (alcohol, 0.79) floats to the very top.
Try pouring them in a silly order in the simulation — water first, then honey, then oil. The tower always ends up the same: honey, syrup, water, oil, alcohol from bottom to top.
Objects pick their floor
Now drop an object in. It sinks past every liquid that is lighter than itself and stops on the first liquid that is denser. A grape (about 1.1 g/mL) sinks through oil and water but floats on syrup (1.37).
A cork is so light (about 0.24 g/mL) it floats on everything, while a metal coin (almost 9 g/mL!) zooms straight to the bottom. Every object finds its own floor in the tower.
Density in real life
Density explains so much of the world! Ships made of heavy steel float because their shape traps light air inside, making the whole ship less dense than water. Hot air balloons rise because hot air is less dense than cold air.
And when you shake a salad dressing of oil and vinegar, watch it afterwards: the oil patiently climbs back to the top, every single time.