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What is density?
Density is a property of a material which relates its mass and volume. If we call an object's mass m
and its volume V
, its density is given by the expression ρ = m/V
. The densities of materials vary dramatically, and are easy to understand relative to one another. If we consider several liquids of different densities (and prone to separation) placed in a container together, we can expect to see them divide such that the most dense settles to the bottom and the rest are stacked in order of decreasing density.
Consider the picture below. The red liquid is the most dense, the yellow is the least, and the black is somewhere in the middle.
Here's a great simulation with objects in a tank of water.http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
Hope that answers your question!
(published on 03/30/11)
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