Gas Laws

Charles' Law

volume follows kelvin temperature

At fixed pressure, volume is proportional to absolute kelvin temperature.

highlighted = computed this step

Use absolute kelvin

At fixed pressure, compare volume to absolute temperature. The first state is 6 cubic meters at 300 kelvin.

ViTi=6 m3300 K\frac{V_i}{T_i} = \frac{6\ \text{m}^{3}}{300\ \text{K}}
Charles comparisonBoth piston states share one volume scale.6 m^32 Pa 300 Kcool8 m^32 Pa 400 Kwarm

Raise kelvin temperature

The second state is 8 cubic meters at 400 kelvin.

VfTf=8 m3400 K\frac{V_f}{T_f} = \frac{8\ \text{m}^{3}}{400\ \text{K}}

The ratio stays constant

Both ratios equal one fiftieth cubic meter per kelvin.

VT=150 m3/K\frac{V}{T} = \tfrac{1}{50}\ \text{m}^{3}/\text{K}
Charles comparisonBoth piston states share one volume scale.6 m^32 Pa 300 Kcool8 m^32 Pa 400 Kwarm