Problem 5
For which level of water in the tank on the left (marked $z$ [m]) will the cone
(orange, see figure) valve open? The valve has a weight of $Q$ [N].
Assume a liquid density of $\rho$ [kg/m³], an earth acceleration of $g$ [m/s²], the
height in the right tank is $H$ [m], the height of the conical ball valve is $h$ [m]
(the diameter of the valve base is $D$ [m], the diameter the small half-sphere
inside the cone (orange) valve is $d$ [m]).