The pound-force or simply pound (abbreviations: lb, lbf, or lbf) is a unit of force. The pound-force is about equal to the gravitational force applied on a mass of one pound on the surface of Earth. Since the 18th century, the unit has been used in low-precision measurements. In the 20th century, people needed a more precise definition. An official value for acceleration due to gravity was needed. Today, as decided by the General Conference on Weights and Measures, standard gravity is usually taken to be 9.80665 m/s2 (about 32.17405 ft/s2)
Other pages [change]
- "Declaration on the unit of mass and on the definition of weight; conventional value of gn". BIPM: Bureau International des Poids et Mesures. http://www1.bipm.org/en/CGPM/db/3/2/. Retrieved 2011-12-12.