Giai
Kh
i don
g na ng va t he nang bang nhau,
ta c6: W
d = — mv
^ =
—
kx
^
2 2
Ccf na ng cua he: W = —mv^
+ —kx
^ = mv^ = —kA^
2 2
2
,2
= l i^
A^
=l co
^A
^=
>A = ^
V2
=^
V2
=6 V^
(c m)
Vdy chqn dap an
D
Cdu 49:
K
hi no
i v
e t ia hong ngoai, phd
t bie
u na
o sa
u da
y l
a sai
?
A
Ti
a hon
g ngoa
i c
6 t an so nho hofn t an so cua an
h san
g t
im
B
Ti
a hon
g ngoa
i c
6 ba
n cha
t l
a son
g die
n tCr
C Ca
c v
at d n hi$
t d
o t re
n 2000
''C chi pha
t r
a t ia hong ngoai
D Ta
c dun
g n
oi ba
t cu
a t ia hong ngoai la tac dung nhiet
Giai
Cac va
t d
n hie
t d
o t re
n 2000
°C c6 the phat ra t ia hong ngoai,
ti
a
tuf ngoai ,
an
h san
g tr on
g thay
Vdy dap
an C
la sai
Cdu 50:
D
oi vdf
i nguye
n tu
f h id ro , k
hi electro
n chuye
n tC
r qu
y da
o M
ve qu
y da
o K t
hi nguye
n tij
f pha
t ra photon
c6 budrc son
g 0,1026nm
Lay
h =
6,625.10-^'J.s
, e
= 1,6.10
-i
'C va
c = S l oW
s
Na ng lifong cu
a
photon n ay bang:
A 12,
1 eV
B
12
1 eV
C
11,
2 eV
D
1,2
1 eV
Gi^i
Na ng lUcfng cu
a photon :
s = J
^ = ^ -^
^^
-^
^"
^-^^
^^
19 3, 7
10 -J = 12,leV
0,1026.10-Vdy chgn dap an
A
Cdu 51:
Mom en quan t in
h cu
a mo
t va
t r an doi vdr
i mo
t tru
e qua
y c
o din
h
A ph
u thuo
c va
o mome
n cu
a ngoa
i l\ic
gay r
a chuye
n don
g qua
y
cua vat ra
n
B CO
gia
ri dtfcfn
g hoa
c a
m t uy thuoc va
o chie
u qua
y cu
a v
at
r^
n
C kh on
g ph
u thuo
c va
o si
r p ha
n b
o k ho
i Itfcfn
g cu
a v
at rS
n do
i vdr
i
true quay
D da
c trifti
g ch
o muT
c qud
n tin
h cu
a v
at r^
n tr on
g chuye
n don
g
quay quan
h tru
e ay
48
• GiS
i Ch
i tig t
ai th
i T
S S
H,
CD
M6n
V$t
I f