[Knufire]

At Rose-Hulman, we've often had problems using lbf(pounds-force) and lbm(pounds-mass).

The conversation ratio was 1lbf = (32.2 ft/s^2)(1lbm).

http://en.wikipedia.org/wiki/Pound_%28force%29

The cause of many a headache when your error to a large dynamics problem is a small unit error buried deep inside your work...