Key Stage 4
Meaning
Fluid Pressure is the force per unit area on a surface due to particles colliding with that surface.
About Fluid Pressure
- The force responsible for pressure in a fluid is the weight of all the particles above the object.
- The pressure in a fluid decreases with height and increases with depth. The deeper into a fluid the greater the pressure.
- Since pressure increases with depth then the bottom of an object will experience more pressure than the top of the object. This causes a force called upthrust.
Equation
NB: You do not need to remember this equation.
Pressure = (Density of the Fluid) x (Gravitational Field Strength) x (Depth in the fluid)
\( P = \rho g h\)
Where\[ P\] = Pressure at that depth.
\( \rho\) = Density of the fluid (This symbol is a 'rho' not a 'p')
\( g \) = Gravitational Field Strength