A chamber of volume V = 87 l is evacuated by a pump whose evacuation rate (see Note to the foregoing problem) equals C = 10 l/*. How soon will the pressure in the chamber decrease by it η = 1000 times?
Let ρ be the instantaneous density, then instantaneous mass = Vρ. In a short interval dt the volume is increased by Cdt.
So, Vρ = (V+Cdt)(ρ+dρ)
(because mass *** constant in a short interval dt)
