Poundal

The poundal is a non-SI unit of force. It is a part of the foot-pound-second system of units, a coherent subsystem of English units introduced in 1879, and one of several specialized subsystems of mechanical units used as aids in calculations. It is defined as 1 lb·ft·s, or in words, as the force necessary to accelerate a pound of mass at 1 foot per second, per second. 1 pdl = 0.138 254 954 376 N exactly. English units require re-scaling of eithe... more

The poundal is a non-SI unit of force. It is a part of the foot-pound-second system of units, a coherent subsystem of English units introduced in 1879, and one of several specialized subsystems of mechanical units used as aids in calculations. It is defined as 1 lb·ft·s, or in words, as the force necessary to accelerate a pound of mass at 1 foot per second, per second. 1 pdl = 0.138 254 954 376 N exactly. English units require re-scaling of either force or mass to eliminate a numerical proportionality constant in the equation F = ma. The poundal represents one choice, which is to rescale units of force. Since a pound of force accelerates a pound of mass at about 32 ft/s (the acceleration of gravity, g), we can scale down the unit of force to compensate, giving us one that accelerates 1 pound mass at 1 ft/s (rather than at 32 ft/s); and that is the poundal, which is approximately ⁄32 pounds of force. For example, a force of 1200 poundals is required to accelerate a person of 150 pounds... less