The following diagram shows a water tank:
h0
h(t)
Stopper
Water flow
The initial water level in the tank is h0, the water level drops continuously after the stopper is left opened. If this process of draining is continuous, i.e., Δt → 0, the whole process can be described by the differential equation:
dh/√h - √2g (d²/D²) dt = 0,
where h is the water level after time t, D is the diameter of tank, d is the diameter of outflow pipe and g is the gravity constant.
a) Solve the differential equation and express the solution in terms of h.
b) Find the constant of integration in part (a) subject to the initial condition: h(0) = h0.