Cours de méca du point L1 et IUT Mesures Physiques de l`UJF

Johann Collot [e-mail] http://lpsc.in2p3.fr/atlas_new/teachingitem.htm Mécanique L1 & IUT1
Cinématique
 !""#$% &'() !**+

Johann Collot [e-mail] http://lpsc.in2p3.fr/atlas_new/teachingitem.htm Mécanique L1 & IUT1
m
,))
-.
/-/..
01,////.
-2
30.
4
Vt
.
t
.

Johann Collot [e-mail] http://lpsc.in2p3.fr/atlas_new/teachingitem.htm Mécanique L1 & IUT1
12.-
056
U
,5
,
,78
8
u
U=Uu
9.0.
-
,1,
1
:
u
u
∥ u ∥ =u=1

Johann Collot [e-mail] http://lpsc.in2p3.fr/atlas_new/teachingitem.htm Mécanique L1 & IUT1
-.
Ut
Utdt
ut
d U=dUt ut 
=dUt⋅ utUt⋅d ut
dUt⋅ut
Ut⋅dut
dut2 = d1 = 0=dut⋅ut = ut⋅dut  dut⋅ut
⇒2ut⋅dut = 0
dut
ut
∀t ,ut = 1
d U
Utdt= Utd U
d U= Utdt − Ut
U
d U
dt
;;2
2-

Johann Collot [e-mail] http://lpsc.in2p3.fr/atlas_new/teachingitem.htm Mécanique L1 & IUT1
2
2
ut
utdt 
d ut 
d
vt
=d vt
dut
dt =d dt vt = tvt
:
t = d
dt
[] = rad s−1
vtdt 
dvt
dvt
dt = −tut
dvt = −d ut