Question

Pascal Law ( P final = P initial)
is applicable if gravity is ignore and h = 0.
so how can we ignore gravity ?

Answer 1

Gravitational force is GMm/r^2 for which
G is x*10^-8
m is x*10^-27 kg
r^2 of earth is (6400)^2 = 40960000

So from that we can come to a conclusion that the Gravitational force can be neglected for individual molecules