I am trying to run a beam deflection analysis in mechanica and have confused the hell out of myself with the force units. The units specified when creating a force is in-lbm/sec^2. How does this convert to good ole pounds-force? At first I thought it was just a factor of 12 to convert feet to inches, but then I think you need to add in the gravitational constant of 32 also so that 200lbf=76800in-lbm/sec^2. Can I get some insight before I confuse myself even more?