I Mass, Density, Volume

Density

A substance's mass per unit volume.

Unit Density

kg/m3kg/m^3

Formula

Density=MassVolume\text{Density} = \frac{\text{Mass}}{\text{Volume}}

Mass

Measure of the amount of matter a substance contains.

Unit Mass

kgkg

Formula

Mass=Volume×Density\text{Mass} = \text{Volume} \times \text{Density}

Volume

The amount of space taken up by a substance.

Unit Volume

m3m^3

Formula

Volume=MassDensity\text{Volume} = \frac{\text{Mass}}{\text{Density}}

Weights on a Balance

Two weights balanced on a beam on a pivot at its center, positioned at equal distances from the pivot, have equal mass.

W0=W1W0 = W1

If they differ in weight, the heaver weight has to be closer to the pivot. Also the weights multiplied by their distances from the fulcrum are equal.

W1×d1=W0×d0W1 \times d1 = W0 \times d0