Electromechanical products Compabloc 1000

MECHANICS
10
General information
Quantity Units
Name French name Symbol Definition , SI
Non SI,
but accepted
Units and expressions
not recommended
Conversion
Time Temps t minute : min Symbols ' and " are reserved
Intervalle de temps, durée s (second) hour : h for angles.
Period (periodic time) Période (durée d'un cycle) T day : d minute not written as mn
Angular speed
Circular frequency
Vitesse angulaire
Pulsation
ω dϕ
ω =
dt
rad/s
Angular acceleration Accélération angulaire α dω
dt
rad/s2 α =
Speed Vitesse u, v, w, ds
v =
dt
m/s
1 km/h =
0.277778 m/s
Velocity Célérité c 1 m/min =
Acceleration Accélération a dv
a = m/s
(or deceleration) (ou décélération) dt
2
Acceleration Accélération
of free fall de la pesanteur g = 9.81 m/s 2 (approx)
0.0166 m/s
Revolution per minute Fréquence de rotation n s -1 min -1 tr/mn, RPM, TM…
Weight Masse m tonne : t kilo, kgs, KG…
Mass density Masse volumique ρ d m
Linear density Masse linéique
Surface mass Masse surfacique
ρ e
ρ A
dV
d m
d L
d m
Momentum Quantité de mouvement P p = m.v kg.m/s
d S
kg (kilogram) 1 t = 1000 kg 1 pound : 1 lb = 0.4536 kg
Moment of inertia Moment d'inertie J, I I = ∑ m.r 2 kg.m 2 MD 2 kg.m 2
4
pound per square foot = 1 lb.ft 2
Force Force F N (newton) kgf = kgp = 9.81 N
= 42.1 x 10 -3 kg.m 2
Weight Poids G G = m.g pound force = IbF = 4.448 N
Moment of force, Moment d'une force M M = F.r N.m mdaN, mkg, m.N
Torque T 1 mkg = 9.81 N.m
Pressure Pression p
F F
bar
S A Pa (pascal) 1 bar = 105 p = =
Pa
1 ft.lbF= 1.356 N.m
1 in.lbF= 0.113 N.m
Normal stress Contrainte normale σ Pa kg/mm 2 , 1 daN/mm 2 = 10 MPa
Shear stress Contrainte tangentielle, τ MPa = 10 6 Pa psi = pound per square inch
Cission is used 1 psi = 6894 Pa
Friction factor Facteur de frottement µ incorrectly = friction
coefficient ƒ
Work Travail W W = F.I 1 N.m = 1 W.s = 1 J
Energy Energie E Wh = 3600 J 1 kgm = 9.81 J
Potential energy Energie potentielle Ep J (joule) (watt-hour) (calorie) 1 cal = 4.18 J
Kinetic energy Energie cinétique Ek 1/2 J ω 2
1 Btu = 1055 J
Quantity of heat Quantité de chaleur Q (British thermal unit)
Power Puissance P W 1 ch = 736 W
P =
W (watt)
t 1 HP = 746 W
Volumetric flow Débit volumique q v dV m3 /s
q v =
dt
Efficiency Rendement η < 1 %
Dynamic viscosity Viscosité dynamique η, µ Pa.s poise, 1 P = 0.1 Pa.s
Kinematic viscosity Viscosité cinématique ν η stokes, 1 St = 10-4 m2 /s
m
ρ
2 ν =
/s
kg/m 3
kg/m
kg/m 2
J =
1 kgf/cm 2 = 0.981 bar
1 psi = 6894 N/m 2 = 6894 Pa
1 psi = 0.06894 bar
1 atm = 1.013 x 10 5 Pa