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It also applies to the feet of a walking person or machine. Pressure is measured in the SI unit of pascals (Pa). Average ground pressure can be calculated using the standard formula for average pressure: P = F/A. [2] In an idealised case, i.e. a static, uniform net force normal to level ground, this is simply the object's weight divided by ...
The pound per square inch (abbreviation: psi) or, more accurately, pound-force per square inch (symbol: lbf/in 2), [1] is a unit of measurement of pressure or of stress based on avoirdupois units and used primarily in the United States. It is the pressure resulting from a force with magnitude of one pound-force applied to an area of one square ...
Units for other physical quantities are derived from this set as needed. In English Engineering Units, the pound-mass and the pound-force are distinct base units, and Newton's Second Law of Motion takes the form = where is the acceleration in ft/s 2 and g c = 32.174 lb·ft/(lbf·s 2).
Both energy and torque can be expressed as a product of a force vector with a displacement vector (hence pounds and feet); energy is the scalar product of the two, and torque is the vector product. Although calling the torque unit "pound-foot" has been academically suggested, both are still commonly called "foot-pound" in colloquial usage.
The pound-force is the product of one avoirdupois pound (exactly 0.45359237 kg) and the standard acceleration due to gravity, approximately 32.174049 ft/s 2 (9.80665 m/s 2). [ 5 ] [ 6 ] [ 7 ] The standard values of acceleration of the standard gravitational field ( g n ) and the international avoirdupois pound (lb) result in a pound-force equal ...
Other units of pressure, such as pounds per square inch (lbf/in 2) and bar, are also in common use. The CGS unit of pressure is the barye (Ba), equal to 1 dyn·cm −2 , or 0.1 Pa. Pressure is sometimes expressed in grams-force or kilograms-force per square centimetre ("g/cm 2 " or "kg/cm 2 ") and the like without properly identifying the force ...
1.5 psi Decrease in air pressure when going from Earth sea level to 1000 m elevation [citation needed] +13 kPa +1.9 psi High air pressure for human lung, measured for trumpet player making staccato high notes [48] < +16 kPa +2.3 psi Systolic blood pressure in a healthy adult while at rest (< 120 mmHg) (gauge pressure) [44] +19.3 kPa +2.8 psi
1 pound per square inch (psi) ≈ 6,895 Pa; Torque 1 pound-foot ≈ 1.356 N⋅m; Insulation 1 R-value (ft 2 ⋅°F⋅h/Btu) ≈ 0.1761 R SI (K⋅m 2 /W) Various combination units are in common use; these are straightforwardly defined based on the above basic units. Sizing systems are used for various items in commerce, several of which are U.S ...