Consistent Sets of Units

Force MassLengthTimeStressDensityAcc of Gravity
Newtonkg metersec Pa ρspec*103  (kg/m3)9.81 m/s2
Newtonton mm sec MPaρspec*10-9 (tons/mm3) 9.81*103  mm/s2
kN kg mm msecGPaρspec*10-6 (kg/mm3) 9.81*10-3 mm/ms2
Newtongrammm msecMPaρspec*10-3 (g/mm3) 9.81*10-3 mm/ms2
lbflbm / 386.1in secpsiρspec/10,687    or
0.00259 * (ρ lbm/in3)
386.1 in/s2



Material ModulusPoisson RatioDensitySpeed of Sound
Al 71,000 MPaν = 0.33ρspec = 2.8c = 5.0 mm/μs
Steel 200,000 MPaν = 0.32ρspec = 7.8c = 5.1 mm/μs
Al 10.3*106 psiν = 0.330.101 lbm/in3c = 0.20 in/μs
Steel 29 * 106 psiν = 0.320.281 lbm/in3c = 0.20 in/μs