Poundal (pdl or pl)
Poundal (pdl or pl) :
An English unit of force used in engineering. Since traditional measuring systems, including the English system, did not distinguish between force and mass units, the poundal was defined to provide a unit clearly measuring force rather than mass. One poundal is the force that accelerates a mass of one pound at the rate of one foot per second per second. Since the acceleration of gravity averages about 32.174 ft/sec2 at the Earth's surface, one poundal is about 1/32.174 = 0.031 081 pound of force. One poundal is also equal to approximately 0.138 255 newton, or 13 825.5 dynes. The newton, the SI unit, is now the preferred unit of force in engineering and technical work. The poundal was invented in the 1870s by the British mathematician James Thomson, who also named the radian
