 !"#
$%&"#'())(*)+,)
BAÌ GIẢI CHI TIẾT MỘT SỐ CÂU ÐỀ THI TUYỂN SINH ĐẠI HỌC KHỐI A, A1 NĂM
2013
Môn thi : VẬT LÝ – Mã đề : 426
-./01232+45'
6,7
89&:;&<=>?15325'
65(
9&:""
@AB1,5'
)
9@C@DE15'
+

I. PHẦN CHUNG CHO TẤT CẢ THÍ SINH (40 câu, từ câu 1 đến câu 40)
Câu 1: F&<"#
'
 G  = ω
HIJH;
'
G
K
ω
AB&LJK&M&NN!:
>ABM%.#;O&<P&<H>&L&DQJR1
'

SDE
&:T&<@N;#UK
5

d
d
U
U
1,6666]^
+
1,^
5
66666]_
5
1,_
+
6666666_
5
+
1(_
+
+
`
+
aH_

 _
5
J
+
1(`
+
a(H_


1
5
Z
U
6666666]G1G
5

5
5
d
Z
Z
1G
5

++
5
+
5
++
+
L
CLCL
ZR
ZZZZR
+
−++
1G
5
,

5
−
+ 5
+
π
ϕ ϕ
= −
66666]ϕ
5
aϕ
+
1
+
π
66666]ϕ
5
ϕ
+
165HSϕ
5
c'J
R
ZZ
CL 5
−
R
Z
Z
C
L

Z
1'66666666]
+
5CL
ZZ
7_

,
5C
Z
a
,
+
5C
Z
1'666]
,
+
5C
Z
6
2
4
5CL
ZZ
1'
6666]
,
5C
Z

= 90V.
Câu 2:@:=<d6e""3-D;P""&UK2''3
A%"fAg#K5R%"hF#ijA&.K"
K+R%"&DQ@?KP"@W-/
Z53+ [534 '3( \'3,
5
 !"#
$%&"#'())(*)+,)
\k
D
i
a
λ
=
153+5'
−
,
153+
Câu 3:@=<d6e""3.>""&UK-/
""&UKKKf>?"&eA<A"S@?K"
ZA%AB>&L [A%0?
W@=@>&L \A%%l
λ
K
]λ

⇒
K
]


5
G
G
+
+

+
'
+
nZt
=








+








ω
ω


h&P=&AG
l
15,)I
Câu 6 :n:uv&:&eTC@Owl;-?&:43AS+NE&k
1'3u&-/weDUDU@S&:XuK
Z
l 4H  J
+
π
= π −
HJ [
l 4H+  J
+
π
= π −
HJ

l 4H+  J
+
π
= π +
HJ \
l 4H  J
+
π
= π +
HJ
Câu 7:xrX:">#"&<l>e:#K&M&NNZ3[
.#!&<@s2(35

+
+
5
5
+
+
5
+
+
+
+
+
5
5
+
J

5
HJ
5
H
ω
ω
ω
ω
ω
ωξ
ξ
Câu 8 :n:uv&:&eT:|&NiK5+\&:K>P-?
&:K

@?F#iAB"Iuv&/>?sW@=-/3N1'3"Or
y1+x?uvHS~J&:&eT&.E&k

,
π
=
Sh"
Ory\&:&eTXAABTry"OP"@W-?&:gần
giá trị nào nhất &>Y
Z( [55 4 \*
Giải:
az&Mu&sI[SPy"OSu>I[~;Kw•"I[€K
m
K
F
'43'=
= 5cm mà lúc đó v = 0 nên A= OO’ = 5cm. Chu kỳ dao động T =
s5'
π
+ Sau khi vật đi được
5+7
,
5'
,
,
TT
T
T
++==
π

π
=
HIJK&M&NN.#!&<@s
5''R
= Ω
3O&<P
7
5'
+
C
π
−
=
yK:%MP
5
L
π
=
o[kjDE&:T&<
@&NNK
Z
+3+ +  5''
7
i t
π
π
 
= +
 ÷
 

 
HZJ
Câu 12:$%•:<‚@@>eB&&j>?;F&{s:&:
l"&W@F#it=N@"{9&DEi<;@"{&A
&:'@"{D:%M3-"A=K2,*'A3ADQK25'
+7
AKAS>
@OXPK+7E9/{#ƒ$1232*5'
655
x
+
A
+
mPrHq],'nopJ
#"h<@>ei&."&k/@?t=N@"{@A%A&:K
?D;&>Y
ZhA&:*(
'
+'•&.A&:*(
'
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7
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π
17+55+)*5
⇒1,4*7+)*5
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vnx@?S~
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OM R
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α
= = =
+
⇒α1)53,
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1)5
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+'„
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Câu 13:n:!#"P&:&eTN@P@T&!w@>e@?FD;
;-D;Pλo&knKx:FD;3/@?#DU@>ePK"#M
•D;&&:[.wn1)λ3wx15+λKwnBP;wx@?&Nnx3
&kK#M•D;&:DQ#;&:X!wK
Z4 [7 2 \*
$%
f&kDQ#;w"w:&N1HAa'34Jλ;wn1)λ≤≤wx15+λ⇒P7
&k=Q#UA1…)3(35'355†
Câu 14:$Cn3x3^K"&k@?:Tlg3&DQ@i&js&kw&WRT

Câu 15:oNP&:OAK;SP
Z0DQ?A.Kv [0DQ?A.K;
0DQ?A.@?K; \0DQ?A.@?Kv
Câu 16:RPe#BB3#"-kKD;&>&zY
Zx0DQX#BBK;A-D;P""j;#BB&PK;
[BBPk!N@@N"&j>?
I;ˆ""&UPMql"&W3"#BB&e0DQD
\x0DQX#BB""=vU0DQX#BB""&v
Câu 17:@?:Q>&K!K53&M&W3&PPh;4zPHAk%
&M>J[D;PXP@>e@?&>K
Z5 [534 '34 \+
$%
4zP⇒A143λ1+lA1+571'34
R
R h+
O
M
V
α
N
7
 !"#
$%&"#'())(*)+,)
Câu 18:F&<"#1
++' + 5'' t
π
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+'Ω3:%MP&:r%
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Z7Z [5'Z )Z \2Z
$%

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15'
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K
5
12ZK
+ + 5*
5 +
7 53,5'q q
−
+ =
H5J
.
5
15'
6(
KH5J
+ + 5*
5 +
7 53,5'q q
−
+ =
H5J⇒
+
1,5'
6(

Nˆ0P,24K>9ˆ#N@+''nI9Z6B66&@Bx
Z
123'+5'
+,

65
RDQ
+,4
GKT#%j?O@,0K
Z72532A [72532 +,'3)A \+,'3)
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5
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5
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5,
891,,24+7,2''HJ
⇒x1H
5
J⇒1n1xnx
Z
1nH
5
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Z
J1+,')+,1+,'3)+,A
Câu 21:@:=<ePD;3!PA.Q#w
5
Kw

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NαADQ"N
α
173''549

153''*,9
x57
15,3(((+9
w5*
1523((7*
[.51(,534nI
+
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5*
)
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K
Z+3'*4nI [+3+57nI 23574nI \53,74nI
$%
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p O
p p p
α
= +
r r r
S
p
p p
α
⊥

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w
1+3'*4nI
4
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$%&"#'())(*)+,)
Câu 23:$;N&<X:ANK'3*4µB"?@@AvANK>
-/
Z+3245'
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8 [+2345'
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8 +3245'
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8 \+2345'
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8
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A
λ
=
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Câu 24:F&<"#1G
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ωHG
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6)
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6)
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Câu 27:n:PS&@>e@?:Q>e
DUX@OwloS~B%SNXQ>NE&k
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5
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+
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5
a'3,HJH&DEe‡J
NE&k
+
3uX&kx@?&>K
Z2437 [62437 6,(3, \,(3,
Giải:
+ Từ hình vẽ dễ dàng thấy:
cm7'=
λ
Tốc độ truyền sóng: v= 15/0,3 = 50cm/s
Chu kỳ sóng: T= 40/50 = 0,8s
+ N đang ở VTCB và dao động đi lên vì vậy:
V
N
= v
max

@O&ljH:F#iXAJ@h@DE&ePU%jhBP;
@O>KP&:;'37hBr&NA>K
Z+375'
6,
- [53+5'
6,
- 73)5'
6,
- \'325'
6,
-
$%
BSΦ =
1'372'5'
−
7
1+375'
6,
-
Câu 30:<0&DQ@>ehU#"&.:AD-/&DE>:#;<
{@>e%K('‹#=&<0}v<@?&DE>KABDQ"
+'‹x.B{•O&<XADK>0+'‹Kf>?&<"#sU#"
S<{@>e%&<0@?=&DE>&PK
Z)43)‹ [)*3*‹ )(3+‹ \(+3)‹
2
 !"#
$%&"#'())(*)+,)
Câu 31:[.-"A=[K@
'
143,5'

3l
+

t
5
1ZH
J
+(3'
ππ
+t
9t
+
1ZH
J
+)3'
ππ
+t
ao>Al
5
1l
+
%SP

1'37+,
Câu 33:n:uv&:&eT#DU@Sl1Z7πH=-/J=h1'3
A%E{&kXuP&:;-/:•&:;r&NK
Z'3'), ['35+4 '35'7 \'352*
$%
121'342155+1'3'),,,,
Câu 34:o&:&eT‚#DU3‚MP-?&:MDQKZ

]

ε
[

ε
]
ε

]
I
ε

I
ε
]

ε
]
ε

\

ε
]
I
ε
]
ε


G
KN
+,)
G
K
,
5''
Y
Z+3*7}0 [+3++}0 53*7}0 \,354}0
Câu 37: @?:&DEi&W@B@DE&iD;3AB{#OK#%lN
3:">s"!:A%&DQPjDE&:K9AW
>k">@l!?(SjDE&:&DQK +'H[JR%
"K
Z) [5 ( \5'
Câu 38: @AB3""P-D;P;{@"""&U&v3
K33=K
Z""= [""&v ""K \""
Câu 39: NN.#!
:%M3&NNtKO&<HS~J
*
 !"#
$%&"#'())(*)+,)
R&FK&MZ3[&<"#
Z[ '
 G H  J= ω + ϕ
HIJHG
'
3
ω
K

$%
aS
+
 5ω =
?G

1G

u>
Z[
1
t
aP
Zx
a
n[
1

a
t
a
t
a

1+
t
1+
Z[
ABMBAN
UUU +=+→

d t
t t
W W W
A x
W W x
−
−
= =
15
Câu 41 : RPe#LN#"lN3#"-kK&>K saiY
Z#LN#"lNX:>?K:<fN"@?•30
"-sfA%
[#LN#"lN{@F{v#"@A-WP
@#LN#"lNX>?•&@B3s‚""S{>P-N
&F@DKN&v3N3NKKN=
\#LN#"lNX">?"CA"SA"
\k
Câu 42: n:N=Ds&r<&:&<hr[.&<=r&NXO
&<K
'
KDE&:T&<r&N@NK^
'
NE&kDE&:T&<@
N-/'4^
'
S&<=XO&<P&:;K
Z
'
 +
+

Z) [52 27 \,+
$%
171+⇒m1+7Z1+771,+
Câu 45: n:&UPeK5+53&:&eTNUP@C@DE
{>
+
5'π =
AS&:XK
Z5 ['34 +3+ \+
+
l
T
g
π
=
1+3+
Câu 46: $%•:!"}#"@""&UPM*45'
57
opB{#"
lNX!K5'm#BBK!"#"@@:>l{#l}-/
Z'3,,5'
+'
[+3'55'
5(
'3,,5'
5(
\+3'55'
+'
W N Nhf
P

π +
 ÷
 
HZJo<B{
X&NN-/
Z53'' ['3)* '3*5 \'34'
ϕ1ϕ

−ϕ

1−π2ϕ1'3)22
Câu 48: r<=<d6e;""&UP-D;P
λ
R%
"fAg#K5@?K"3N&kn"@73+P
"-u4$f&W"&eA<A"3>kMK"C&DEi
BP;F#ijA@l&.ANn>kK
MjSA%WKK'32[D;P
λ
-/
Z'32
µ
['34
µ
'37
µ
\'3*
µ
$%
153l173+

Z5' [55 5+ \(
l l
k
λ λ
−
< <
Câu 50: F&<"#l>e1G
+

ω
HIJK&M:&<@sM`155'
Ω
S
DE&:T&<&<@sP"@W<O-/+Z$"@WXG-/
Z++'I [++'
+
I 55'I \55'
+
I
$%
G1^`1++'
(
 !"#
$%&"#'())(*)+,)
B. Theo chương trình Nâng cao (10 câu, từ câu 51 đến câu 60)
Câu 51: n:u@>:@O
∆
&W;&:P,'@n"=X
u@&;@O
∆

q H J

−
Câu 54: n:TlPADQuvK
5
 ,''=
&:&eT;AS5
x.>uvPADQ
5
-/uvPADQ
+
S&:;AS
'34$"@W
+
-/
Z5'' [54' +4 \*4
Câu 55: F:&<"#l>eP"@W<OAB&LKMq>&L&DQK
&M::%MRq14'opSDE&:T&<:%P"@W<
O-/,ZRq12'opSDE&:T&<:%P"@W<O-/
Z,32Z [+34Z 734Z \+3'Z
Câu 56: nN&:=Ds&N&:3&<=r&NXO&<K
2
'
 5' 
−
=
K
DE&:T&<r&N@NK
'
^ , Z= π

54
x
52
[
'
5
x
52

'
5
x
7
\
'
5
x
)
Câu 58: o%MvPADQMDQK+37AK'32As&M:j
Kgn"=X<&;@O>&@&kXKBP;
K'35+A
+
eKXK
Z'37 ['32 '3) \'3,
Câu 59: n:-"l&>&e@O
∆
&W;&:0K++48[.
"=X-"l&;@O
∆
K+A