|
Quantity
|
Symbol
|
Unit
|
Unit’s symbol
|
Relationship
|
|
Displacement
|
l
|
meter
|
m, km, mm
# in, mile
|
# 1 in = 25.4 mm
# 1 mile = 1.609 km
|
|
Mass
|
m
|
kilogram
|
kg, t
|
1 ton = 1000 kg
|
|
Time
|
t
|
second
|
s, min, h
|
1 minute (min) = 60 s
1 hour (h) = 3,600 s
|
|
* Angular displacement
|
θ
|
|
rad
|
1 rad = 180/π o
|
|
Area
|
A (l2)
|
|
m2, cm2,
mm2
|
|
|
Volume
|
V (l3)
|
liter
cc (cm3)
|
m3, L,
cc
# gal, in3
|
l L = 1000 cm3
(cc)
# 1 in3 = 16.3871
cc
= 0.01639 L
# 1 Gallon (US) = 3.7854 L
# 1Gallon (UK) =
4.5461
L
|
|
Velocity
|
v (l/t)
|
|
m/s, km/h
# mile/h (mph)
|
1 m/s = 3.6 km/h
# 1 mile/h = 1.609 km/h
|
|
* Angular Velocity
|
ω
N
|
|
rad/s, rpm
|
ω = 2π N/60
|
|
Acceleration
|
+ a (l/t2)
|
|
m/s2
|
(km/h)/s [car]
|
|
* Angular Acceleration
|
α
|
|
rad/s2
|
|
|
Force
|
F (m.a)
|
Newton
|
N, kN
|
1 N = 1 kg m/s2
|
|
Weight
|
w, G
|
Newton
|
N, kN
# lb
|
w = m.g = m x 9.81
# 1 lb = 4.44822 N
|
|
Pressure §
|
p (F/A)
|
Pascal
|
Pa, kPa, MPa
# psi
|
1 Pa = 1 N/m2
1 MPa = 1 N/mm2
# 1 psi = 6894.76 Pa
|
|
Torque
|
T (F.l)
|
|
N.m
# lb.ft
|
# 1 lb.ft = 1.356 N.m
|
|
Energy, Work
|
W (F.l)
|
Joule
|
J, kJ
#Btu
|
1 J = 1 N.m
1 J = 1 W.s
# 1 Btu = 1.05506 kJ
|
|
Power
|
P (W/t)
|
Watt
horsepower
|
W, kW
PS, #bhp
|
1 Watt = 1 N.m/s
= 1 J/s
P = T.ω [engine]
P = F.v [car]
1 PS = 75 kg.m/s
# 1 bhp = 550 lb.ft/s
1 kW = 1.36 PS
#1 bhp = 1.0142 PS
#1 bhp = 0.7457 kW
|
|
Density
|
ρ (m/V)
|
|
kg/m3,
kg/L
# lb/ft2
|
# 1 lb/ft3= 16.018
kg/m3
|
|
Fuel Consumption
|
|
|
kg/h,
L/h
L/(100 km), km/L
# mile/gal
(mpg)
|
[engine]
[car]
# x mile/gal
(US)
= x
/ 2.353
km/L
= (235.26/x)
L/100
km
# x mile/gal
(UK)
= x /
2.825 km/L
= (282.48/x)
L/100
km
|
|
Temperature |
tc |
Degree Celsius |
oC, K (Kelvin),
# oF (Fahrenheit) |
x Kelvin
= x - 273.15 oC
# x oF
= (x - 32) 5/9 oC |
|
Calorific value |
|
|
kJ/kg
# Btu/lb |
# Btu/lb = 2.324 kJ/kg |
|
Standard gravity |
g |
|
|
9.80665 m/s2 = 32.1740 ft/s2 |