543 B
543 B
Fluids Pressure is perpendicular force acting on a surface divided by area.
Summary
P=\frac{F_\perp}{A}- Scalar.
- Incompressible fluids keep constant density and volume when pressure changes.
P=P_0+pgh- At the fluid surface h is 0.
- Measured in pascals (1 Pa = N/m^2)
Absolute vs Gauge Pressure
Absolute pressure is total pressure: P=P_0+pgh, where P_0 is a reference pressure such as atmospheric pressure (P_{atm}) and gauge pressures is pgh. Positive gauge pressure means above atmospheric, negative means below.