8/8/2019 2me bac _devoire N1 de physi _

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a=0,5cmN=100Hz (S) v=10m/s -12- S = 1m.3- S . t = 27,5ms -

d = 0,15m M - M S -

: O .

N = 25Hz. . -1 -2.Ns -3

:

C = 3.108m/sv = 400nmR = 750nm.A- a = 10m . E D = 1m .

-12- a -3B- A = 60.

DR i =50 =57,78.1- i -2

: V1=100ml H2C2O4C1=8.10

-2mol/lV2 = V1 (2K

+,Cr2O72-)C2=2.10-2mol/l.

1-

2- Cr3+ -3

.3.1- [Cr3+]3.2- t =35s -3.3

:+ 3272

/CrOCr4222/ OCHCO

com.hotmail@bac-top ) ( ...........

Prof : med Amine

[Cr3+

] (mmol/l)

t(s)