Pressure in a fluid at rest increases with depth due to the weight of the fluid above.
Pascal's Principle states that a change in pressure applied to an enclosed fluid is transmitted undiminished throughout the fluid.
The pressure at a given depth in a static fluid is given by $P = P_0 + \rho gh$, where $P_0$ is the surface pressure, $\rho$ is the fluid density, $g$ is gravity, and $h$ is depth.
Absolute pressure includes atmospheric pressure, while gauge pressure measures pressure relative to atmospheric pressure.
In hydraulic systems, Pascal’s Principle allows for force multiplication, enabling smaller forces to lift heavier loads.
Review Questions
What happens to the pressure in a fluid as you go deeper?
State Pascal's Principle and explain its significance in hydraulic systems.
How do you calculate the pressure at a certain depth within a fluid?
Related terms
Pascal (Pa): The SI unit of pressure equivalent to one Newton per square meter.
Hydrostatic Pressure: The pressure exerted by a fluid at equilibrium due to the force of gravity.
Atmospheric Pressure: The pressure exerted by the weight of air in Earth's atmosphere, approximately equal to 101,325 Pa at sea level.