Density

Density is its mass per unit volume.

ρ = ^m⁄_v

where ρ = density of object (in kgm^-3)
           m = mass of object (in kg)
           v = volume of object (in m³)

SI Unit: kg m^-3
Other common unit:g cm^-3
1 g cm^-3 = 1000 kg m^-3

Scalar quantity

For pure substance, it is a fixed property.

Different outcomes when an object placed in a liquid:
density of object  ˂ density of liquid => float
density of object  = density of liquid => suspend
density of object  ˃ density of liquid => sink

Note that when an object is made of more than one material, then consider its average density.

Average density = ^{total mass}⁄_{total volume}

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