(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A tank of constant volume V contains air at an initial density pi. Air is discharged isothermally from the tank at a constant volumetric rate of Q (with SI units of m^3/s). Assuming that the discharged air has the same density as that of the air in the tank, find an expression for the density in the tank, p(t).

There's also a diagram of the circular control volume V with one outlet which air escapes at Q.

2. Relevant equations

Mass conservation equation is integral of (p dv) + integral of (pv*dA) = 0

3. The attempt at a solution

I got the equation down to dp/dt = (-pi*Q)/V but that's not right so I'm not sure what to do from here.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Finding the density inside a tank as air escapes

Have something to add?

**Physics Forums | Science Articles, Homework Help, Discussion**