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Pascal's law
Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same.[1] The law was established by French mathematician Blaise Pascal.[2]
Contents
[hide]
1 Definition
2 Explanation
3 Applications
4 See also
5 References
Definition[edit source | editbeta]
Pressure in water and air. Pascal's law applies only for fluids.
Pascal's principle is defined
A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid
This principle is stated mathematically as:
is the hydrostatic pressure (given in pascals in the SI system), or the difference in pressure at two points within a fluid column, due to the weight of the fluid; ρ is the fluid density (in kilograms per cubic meter in the SI system); g is acceleration due to gravity (normally using the sea level acceleration due to Earth's gravity in metres per second squared); is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in metres in SI).
The intuitive explanation of this formula is that the change in pressure between two elevations is due to the weight of the fluid between the elevations. Note that the variation with height does not depend on any additional pressures. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughoutthe fluid.
Explanation[edit source | editbeta]
The effects of Pascal's law, as Pascal discovered in his 1646 barrel experiment
If a U-tube is filled with water and pistons are placed at each end, pressure exerted against the left piston will be transmitted throughout the liquid and
Pascal's law or the principle of transmission of fluid-pressure is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same.[1] The law was established by French mathematician Blaise Pascal.[2]
Contents
[hide]
1 Definition
2 Explanation
3 Applications
4 See also
5 References
Definition[edit source | editbeta]
Pressure in water and air. Pascal's law applies only for fluids.
Pascal's principle is defined
A change in pressure at any point in an enclosed fluid at rest is transmitted undiminished to all points in the fluid
This principle is stated mathematically as:
is the hydrostatic pressure (given in pascals in the SI system), or the difference in pressure at two points within a fluid column, due to the weight of the fluid; ρ is the fluid density (in kilograms per cubic meter in the SI system); g is acceleration due to gravity (normally using the sea level acceleration due to Earth's gravity in metres per second squared); is the height of fluid above the point of measurement, or the difference in elevation between the two points within the fluid column (in metres in SI).
The intuitive explanation of this formula is that the change in pressure between two elevations is due to the weight of the fluid between the elevations. Note that the variation with height does not depend on any additional pressures. Therefore Pascal's law can be interpreted as saying that any change in pressure applied at any given point of the fluid is transmitted undiminished throughoutthe fluid.
Explanation[edit source | editbeta]
The effects of Pascal's law, as Pascal discovered in his 1646 barrel experiment
If a U-tube is filled with water and pistons are placed at each end, pressure exerted against the left piston will be transmitted throughout the liquid and