The open tank in figure contains water at 20°C and is being filled and
emptied by sections 1 and 2 respectively. Assume incompressible flow.
$V_1 = 10 m/s$
$D_1 = 5 cm$
$V_2 = 1 m/s$
$D_2 = 7 cm$
$d = 1 m$
Tasks:
1. Derive an analytic expression for the water-level change dh/dt in
terms of arbitrary volume flows ($Q_1$, $Q_2$) and tank diameter d.
2. How long will it take to raise the level h of the water from 2 meters
to 5 meters (in seconds)
