What is Pressure: Definition and 1000 Discussions

Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure.
Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as 1⁄760 of this. Manometric units such as the centimetre of water, millimetre of mercury, and inch of mercury are used to express pressures in terms of the height of column of a particular fluid in a manometer.

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  1. S

    Mercury vapor from blood pressure devices

    I came across some articles about the health hazard from broken mercury-based sphygmomanometers. This led me to think about vapor leakage from good devices during normal operation. The top of the glass tube is at ambient atmospheric pressure. There is supposed to be a membrane at the top that...
  2. K

    I What is the Ideal Plasma Pressure for Successful Fusion?

    I am trying to wrap my head around the concepts in fusion. They talk about ion density, but I don't ever see that expressed in pascals, for instance. Why is that? I understand that confinment time is also important for successful fusion and that they go hand in hand, but I'm not concerned about...
  3. anonymous99

    Why doesn't atmospheric pressure crush us?

    H
  4. OriginalH1h

    Pressure Required to propel something a long distance

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  5. Fuux

    Sticky card Application of Bernoulli / Pressure incorrect?

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  6. S

    Compressed air pressure vs hydrostatic pressure

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  7. S

    Calculate the Pressure that Shrink film exerts on a cylinder

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  8. obstinatus

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  9. fsonnichsen

    Sodium Vapor Lamps (low pressure) for spectral calibration and diffraction work

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  10. G

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  11. brotherbobby

    Gauge pressure due to a floating body

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  12. P

    Constant Pressure Specific Heat in terms of Entropy and Enthelpy

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  13. C

    Schematics of a high pressure water switch

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  14. E

    Deriving the electrostatic pressure of a water droplet

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  15. brotherbobby

    Gauge pressure of water oozing out of a pipe

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  16. Thijske

    How to calculate the pressure of an explosion?

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  17. brotherbobby

    Pressure due to two liquids in a U-tube

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  18. ib43

    Thermal physics problem -- Pressure and temperature of air in a refrigerator

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  19. C

    Maintaining higher air pressure in an "open" leaky container

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  20. T

    Is cavitation worse at depth? (Fluid pressure and Vapor pressure boiling)

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  21. R

    Could pressure washers solve the Australia bushfires problem?

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  22. bigyabbie

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  23. vxiaoyu18

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  24. Ayrflyer

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  25. D

    Accounting for Liquid Water Density in Ideal Gas Pressure Calculations

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  26. B

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  27. T

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  28. T

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  30. Uchida

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  31. T

    Difference between Absolute and Gauge Pressure

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  32. carveranderson

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  33. T

    Impact of Atmospheric Pressure on the Water in a Tank and a Pipe

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  34. Aletag

    Work done BY the gas in a cyclic thermodynamic process

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  35. maxelcat

    Pressure of an ideal gas -- A Level Multiple Choice Problem

  36. D

    Isothermal process involving changes in Volume and Pressure

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  37. X

    Measure flow rate with a manometer (pressure gauge)

    Hello! I have a volume of 50 liters which I pressurize with air so that I read 1 bar on the manometer. But there is a leakage in the volume so after 30 sec the manometer shows 0,5 bar. What is then the air flow ( liter / min) of the leakage?
  38. E

    Confused about use of external vs internal pressure in thermodynamics

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  39. A

    High pressure gas discharge fusion

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  40. T

    Engineering Understanding Force / Pressure Equation

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  41. Emanuel Silva

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  42. C

    Combine 3 Eqns for Plasma in a Solenoid

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  43. F

    Is Voltage a measurement of pressure?

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  44. T

    Repost/Merged Threads - Density: pressure and temperature dependency

    See image
  45. F

    What Happens When You Dive Too Deep?

    Hello, Human breath the following way: air at ambient pressure is pushed into the lungs during the inhaling phase because the air pressure inside the lungs is lower than ambient pressure: ##p_{inside}<p_{outside}##. During the exhaling phase, the air pressure inside the lungs becomes instead...
  46. TOMMiB

    The Pressure in Interstellar Space.

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  47. Kaushik

    Pressure on a sample of fluid (at rest)

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  48. B

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  49. F

    Why is static pressure called "static"?

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  50. sebastian281172

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