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.