Vay chgn dap an C.. Vdy chqn dap an C.
Trang 1Ta co : L , =
l Ol g^
-=
60 ^ I g^
-=
6 ^ I , =
'l^
^0
K
Suy ra : ^
- = 10'
Vi ci/orn
g d
o am t
i l
e nghic
h vdr
i b in
h phiTOn
g khoan
g eac
h R
den
nguon
am nen :
IL = M
= I O^
C:
>^
= 10 0^
R^
^1 00
Goi M la trung die
m cu
a AB T
a eo : R , =
^^
y^
^ 50R,
Do do ^
= M = 2
^L 50
^
V.y
1 ,=
JV = ^ = 400I
Ta co : = 101g|^
= l Ol g^
^ = 101g400
= 26,
2 «
26
Vay chgn dap an
C
Cdu 3:
T ro ng t
hi nghie
m Y-an
g v
e gia
o tho
a an
h sang , ha
i kh
e
dLfore
chieu bang d nh sang do n sac c6 bifd
c son
g 0,
6 |xm Khoan
g eac
h giOf
a
vhai kh
e l
a 1 m
m, khoan
g eac
h tC
f m
at phan
g chuf
a ha
i kh
e de
n ma
n
quan
sat l
a 2,
5
m, b
e ron
g mie
n gia
o tho
a l
a 1,2
5 cm Ton
g s
o va
n
sdng v
a va
n t
oi c
6 tron
g m ie
n gia
o tho
a la :
A 2
1 van B
1
5 van C
1
7 van D
1
9 van
Giai
in , '
— 0,6.10-^2,
5 , , , ^
Khoang
van: 1
= — =
-; = 1,5.10 m
= 1,5mm
a 1
0 ^
So va
n s6ng
:
N,
= 1
^
^ +
1 =
9 van
— =
8 van
Tong
so van : N
= N
i +
N2 =
9 +
8 =
17 van
Vdy chqn dap an
C
54 " Gi
&i Ch
i tiS
t
(J6 th
i T S
B
H, C
D
M6n Va
t
If