lb·ft/s

pound foot per second

Momentumexact by definition

The pound foot per second is one avoirdupois pound of mass moving at one foot per second, exactly 0.13825495438 kg·m/s. The value is exact because the pound and the foot are exactly defined. Note that the mass pound is intended here, not the pound-force.

Watch out: This unit and the pound-force second look almost identical in writing but differ by a factor of 32.174, the numerical value of standard gravity in ft/s². One is mass times velocity and the other is force times time. Check whether the pound in the expression is lb or lbf before converting.

1 lb·ft/s 0.13825495 kg·m/s