What is Density?
- Density is a physical property of matter
- Density defined in a qualitative manner as the measure of the relative "heaviness" of objects with a constant volume.
- Density may also refer to how closely "packed" or "crowded" the material appears to be – think of a styrofoam vs. ceramic cup.
Density = Mass / Volume
We can use this density triangle to easily isolate a desired variable.
D = M / V
M = DV
V = M / D
For a solid we usually (but not all the time) use g/cm3
For a liquid we usually use (but not all the time) use g/ml
Water and Density
1 cm3 of water = 1 mL
Density of water = 1.0 g/mL
Or = 1000 g/L
The density of many substances is compared to the density of water. Does an object float on water or sink in the water
D object > D Liquid = sink
Example. A rock sinks into water
D object < D Liquid = float
Example. A piece of wood will float on water.
Check out this video for a cool density experiment:
Check out this video for some density problems: