A tank of volume V. is filled initially with air at atmospheric density pa,. Beginning at t = 0, a pump delivers to the tank a mixture of air and water. The volumetric inflow rate to the pump is Q, half of which is water having a density pw, and the other half is air at the densitypat . Once inside the tank, the water falls to the bottom, occupying a volume Vw(t) that increases with time (see Figure 1). The air rises to the top of the tank, forming a volume with uniform density pa(t). In terms of the known quantities V. , pat , Q and pw derive expressions for Viv(t) and pa(t) as functions of time t.
