Section 11
Fluid mechanics
Mass per unit volume.
Ratio of the perpendicular force to the area.
The pressure in a fluid at rest increases linearly with depth.
Equivalently
The pressure difference between two points in a fluid at rest depends on the height difference.
for a homogeneous static fluid.
In a hydraulic press
A pressure change is transmitted equally; the forces are related by the ratio of the areas.
The buoyant force is the weight of the displaced fluid.
Volume of fluid crossing a section per unit time, equal to the product of area and speed.
General form
The product of area and speed is conserved along a duct for an incompressible fluid.
Condition for the first form: incompressible fluid.
Between two points
Along a streamline, the sum of pressure, kinetic term, and gravitational term is constant.
- steady, incompressible, non-viscous flow, applied along a streamline.
particular case of Bernoulli for the exit speed of an ideal fluid.
Mass of fluid crossing a section per unit time.