# Boyle's Law

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Boyle's Law, one of the gas laws, is one derivation of the Ideal Gas Law.  An alternate derivation is Charles' law.  Boyle's law states that the volume occupied by a given mass of gas varies inversely with the absolute pressure if the temperature remains constant.  For a fixed amount of gas kept at a fixed temperature, $$p$$ and $$V$$ are inversely proportional (while one increases, the other decreases).  Boyle's law assumes that there is no temperature change in the process.

## Boyle's Law formula

$$\large{ p_1 \; V_1 = p_2 \; V_2 }$$
Symbol English Metric
$$\large{ p_1 }$$ =  pressure at state $$\large{\frac{lbf}{in^2}}$$   $$\large{\frac{N}{m^2}}$$
$$\large{ p_2 }$$ =  pressure at state $$\large{\frac{lbf}{in^2}}$$ $$\large{\frac{N}{m^2}}$$
$$\large{ V_1 }$$ = volume at state $$\large{ ft^3 }$$ $$\large{ m^3 }$$
$$\large{ V_2 }$$ = volume at state $$\large{ ft^3 }$$ $$\large{ m^3 }$$