LBM vs. LBF (and Slugs)

Reprinted from,

Ed Gohmann
Purdue University School of Technology
New Albany, Indiana


In the meter-kilogram mass-second system it is defined that one Newton (N) of force will accelerate 1 kilogram mass (kgm) 1 meter per second squared. Thus for the mkgs system

1/K = 1 N*sec2/kgm/m

or practically

F (N) = m a kgm*m/sec2

A parallel is found in the English system which defines that 1 pound force (lbf) accelerates 1 slug mass 1 ft/s2 resulting in

1/K = 1 lb(force)*sec2/slug/ft

or

F(lbf) = ma slug*ft/sec2

Quite often in this system mass is given in pounds mass (lbm) with the fact that one slug equals 32.17 lbm. Thus to obtain slugs when given lbm you divide by 32.17 lbm/slug.





Going the Big Inch!