All Problems

Equation of the gas state processes

Problem 2.7

A vessel of volume VV is evacuated by means of a piston air pump. One piston stroke captures the volume ΔV.\Delta V . How many strokes are needed to reduce the pressure in the vessel η\eta times? The process is assumed to be isothermal, and the gas ideal.

Reveal Answer
n=lnηln(1+ΔV/V)n=\frac{\ln \eta}{\ln (1+\Delta V / V)}