In an apartment block of 5 floors water is fed from tanks(reservoirs) at the top. What approximately is the pressure in bars versus the height in metres? None of the hot water cylinders have pressure reducing valves fitted.

In an apartment block of 5 floors water is fed from tanks(reservoirs) at the top. What approximately is the pressure in bars versus the height in metres? None of the hot water cylinders have pressure reducing valves fitted.
assumed total height is 15.25 M(50ft); 50 x 0.433= 21.7, 21.7 + 14.7 =36.4, 36.4/ 14.7= 2.48 bars... a water column at 1 ft H would have the pressure of 0.433 psig or 15.1 psia

A piece of copper whose density is 8.9 gr/cc. weighs 200 grams. In water. What is the weight of copper in air? What is its volume?