Question

not-so-well-known unit of mass in the English system is the pound-mass, abbreviated lbm, where 1 lbm = 0.454 kg. What is a density of 8950 kg/m3 in units of 1bm per cubic foot?

Answer 1

1 m = 39.37 in / (12 in/ft) = 3.28ft

1 m^3 = 35.31 ft^3

If 1 lbm is equivalent to .454 kg then

1 kg = 1.00 kg / .454 kg/lbm = 2.20 lbm

8950 kg * 2.20 lbm/kg = 19,714 lbm

ρ = M / V = 19714 lbm/35.31 ft^3 = 558 lbm/ft^3