Hydrostatic pressure or fluid pressure

The hydrostatic pressure of a column of liquid :

p= ρgh

• ρ  density of the fluid in kg m^-3  
• g   gravitational acceleration in ms^-2
• h   height of the column fluid in m

Example

a. Calculate the pressure of water at a depth of 70 m.

       p=  ρgh = (1.00 x 10³)( 9.81)( 70) = 6.87 x 10⁵  Pa

b. Calculate the total pressure p’ at a depth of 70 m

p’ = p + p_A  = 6.87 x 10⁵  + 1.0 x 10⁵ = 7.87 x 10⁵ Pa

p_A  atmosphericpressure

c. Calculation of the total force F’ on a area of 1.00 km²  at a depth of 70 m

F’ = p’A = (7.87 x 10⁵)( 1.0.10⁶) = 7.87 x 10¹¹  N

       ( A in m²)