1
Table 1-4 Variables and Units
Base Units in Boldface - Abbreviations in ( )
Variable
Symbol
ips unit
fps unit
SI unit
Force
F
pounds (lb)
pounds (lb)
newtons (N)
Length
l
inches (in)
feet (ft)
meters (m)
Time
t
seconds (sec)
seconds (sec)
seconds (sec)
Mass
m
lb-sec2/in (bl)
lb-sec2/ft (sl)
kilograms (kg)
Weight
W
pounds (lb)
pounds (lb)
newtons (N)
Pressure
p
psi
psf
N/m2 = Pa
Velocity
v
in/sec
ft/sec
m/sec
Acceleration
a
in/sec2
ft/sec2
m/sec2
Stress
psi
psf
N/m2 = Pa
Angle
degrees (deg)
degrees (deg)
degrees (deg)
Angular velocity
radians/sec
radians/sec
radians/sec
Angular acceleration
radians/sec2
radians/sec2
radians/sec2
Torque
T
lb-in
lb-ft
N-m
Mass moment of inertia
I
lb-in-sec2
lb-ft-sec2
kg-m2
Area moment of inertia
I
in4
ft4
m4
Energy
E
in-lb
ft-lb
joules = N-m
Power
P
in-lb/sec
ft-lb/sec
N-m/sec = watt