What is the maximum gauge pressure of waters that can measured using piezometer tube 2m high?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

Particles vibrate in a rigid structure and do not move relative to their neighbors.

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure