The pressure value is given by the equation,

Where,
represents the density of the liquid
g= gravity
h= Heigth
A) For the measurement of the guage pressure we have the data data,



Replacing we get,

P_g = 12395Pa[/tex]
In order to find the Absolute pressure, we perform a sum between the atmospheric pressure and that of the Gauge,
B) The atmospheric pressure at sea level is 101325Pa, assuming ideal conditions, we will take this pressure for our calculation, so

Explanation:
The given data is as follows.
= 400 K,
= 500 K,
= 25 kJ = 25000 J (as 1 kJ = 1000 J)
Now, we will calculate the change in entropy as follows.

Putting the given values into the above formula as follows.

=
= 250 J/K
Hence, we can conclude that change in entropy is 250 J/K.
The reason you only see fossils in sedimentary rock is that these set of rocks are formed in much lower pressure and temperature, compared to the other types of rocks like igneous rocks.
Gravitational force pushes down on us to keep us on the ground. So it pushes in a downward direction.