Custom $2$:

Water flows through a device as pictured below.

This device has a small tube dropping down from the constriction in the middle into a liquid in the bottle, which has

the same density as water.

The liquid in the bottle is being sucked up the tube by a low pressure in the constriction at point $2.$

Assume that the flow rate of liquid through the vertical tube is negligible.

Find: a$)$ the volume flow rate of water through the device, in gpm $.$ b$)$ the necessary diameter at point $2.$

$Z_1=Z_2=Z_3=\frac{O}{?}$