Who devised for the first time,a method for measuring atmospheric pressure?

If the atmospheric pressure is $P_a$,then the pressure $P$ at depth $h$ below the surface of a liquid of density $\rho$ open to the atmosphere is:

The pressure at the bottom of a liquid tank is not proportional to the

$A$ vertical off-shore structure is built to withstand a maximum stress of $10^9 \; Pa$. Is the structure suitable for putting up on top of an oil well in the ocean? Take the depth of the ocean to be roughly $3 \; km$,and ignore ocean currents.

$A$ tank of oil has a height of $4 \,m$ and a density of $850 \,kg \,m^{-3}$. The gauge pressure at the bottom of the tank is (Given: $1 \,atm = 10^5 \,Pa$,Acceleration due to gravity $g = 10 \,m \,s^{-2}$) (in $\,kPa$)

The figure shows two containers $P$ and $Q$ with the same base area $A$,each filled to the same height with the same liquid. Select the correct alternative.