Question: is lbf equal to lbm?
Answer: lbm represents the mass that weighs one pound-force (lbf) on earth. It is not proper to say that a lbm is equal to a lbf since the former is a unit of mass and the latter is a unit of force. However, it is proper to say that a lbm weighs one lbf (on earth). ... In fact, a slug is 32.174 lbm.