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−#$!%&'$
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,9
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/.90
"0""94%$!",Q

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  8Y  \4    $  
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F(+.9:4>#1Z
[[\4F$
]
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4. Cuỷng coỏ kieỏn thửực (6 phuựt)
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9: !
l@$7C"7g
r@ZQ$7C"7g
:@,-=5/
e:\r,:T

#
:6\sai
r>/,-K
l=7a
/a



 
rf#•7>,-
:#€@$
E
A
 L ,-aQ"d,$+\fC,$+
el:T
#(;@
uTKg,vUSA"TU9Chúng ta đã biết phương trình dao động điều hòa, vậy để xác định được
trạng thái dao động tức là ta cần phải xác định được vận tốc và gia tốc của vật.
u<TN,
1AB-CD.E/ E4FGCD6H
G30I
%&ASAi"TU9T;:K*wx*y=x%=*wN=z{z)Ky
9 D€4,%*,-
  $      
K^
†47,$+,
$+\  f ,- C8
,-%^
 >,-,
%,N">4
a^
,ma‡m−ωlSωnϕU
am±l
⇒
,mW
amW,m±ωl

P @8$f,-
$ˆ"π`B,N
//|m/YDmCD/|
3DEFGFXEY
/vg

US‰
ϕωω
+−==
tAxv
F,
/a
mlω amW9(-#(X:r
F,
/
mW am±l9(-R,$+
KL9(-$ˆ"π`B,N
 (%   * >  
US‰‰‰
B
ϕωω
+−=== tAxva
=g
  $      
K^
H,8C
/!^
FH))
,N,8NŠ
5,NN>


US‰‰‰
B
ϕωω
+−===
tAxva
F‹‹
/a
mlω
B
 am±l9,-R
FmW amWS(X:rU 8
Œ

mW
FH)Q,NSD49
(b0)N,(X:rU
KL:H)),N
,8NŠ5,NN>
%&BSAB"TU9/}%~8j=N=%&%MK8=
FDNyD,<[a
,$$@"ϕmW
FImW9
amlSωU
mlS
B|
X
U
,mFlωS
B|

X
U
/ F•  )  CD  3DE  FG  FX
€D
F(<[$@"ϕmW
 WX`EX`BvX`EX
a lWFlWl
,
WFlωWlωW

Flω
B
Wlω
B
WFlω
B

lω
B

mFlω
B
S
B|
X
U
Fj,-
7@/mW
mX`E
mX`BmvX`EmX

bjgfS•"TU
F:>7 %*,,-,>
FsP,<[>


?,-K #,$+\f8
l,-fW,=7 r,-=7,=7
:,-8N=7S=7U,fW e,-fW,fW


H$KaR9
lmω
B
a rmFωa
B
 :mFω
B
a emω
B
a
B

#
…[ˆa>/Kh@
!X7@/m
E
Xv
,-8,-, 
9
l,mWYm l r,m lYmW

:,m lYmW e,mWYmW
pV@Nq,r,sSA"TU
F:\•d•F$„FGHI
Fr-"AWAA$„FGHI
F:-"R-"
a
,




X
2
T
4
T
4
3T
k
k
k
l
Fl
ω
A
Flω
Flω
B
lω
B




P:>, Z\/ %*,K
F_6Z79…"0$! !,-,[
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!"
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#$%&92345/,5/T 6-"*"/7,8
+-"
'()
$*+9
:;5-",K8Ny1
,9
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-- X4%$!",Q
/E4FG3456
7%89SB"TU9V$-= /$
:;<=>?Si"TU
•K‚9
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U†(X!,-fW^†(X!fW^
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#(vU
1AB-CD.E/ E4FGCD6H G30I
%&ASA‚"TU9s/-"ƒ‚„AW$GHI$„
FH6/6*-46
-"9ƒ‚„AW

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F:N"$E8//$B
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5$1@",1+
F:8/-5/,.1
-
FH1+9
r‚I/,-4
$K,N8π$`!
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+gK,N
p88
X89Xm
B B
π π
ω π
=
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A A
X B
=
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r„X89amFiSEπUS/U
miSEπnπUS/U
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rƒ…":
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r„…"e
rAWXd"0$!9

lmB/Yϕm
•
π
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•
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rAWXd"0$!9
lmB/Yϕm
•
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UA‚/

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A
B
X
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,9xmA`XmBD}
%&vSƒ"TU:M-"A„$GrX$E
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-"
:?9Xh!,<,!Sωn
B
π
U
m[Sωn
B
π
UF
B
π
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>/c$$.4
5>/
$$.a
rA„
Xh!,<,!Sωn
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Um
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>/c$$.4
5>/$$.a
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p`V@Nq,r,sSA"TU
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479
474
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1. Kiến thức
k
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F(%9:)*= b,.,,-KY:)*+ !>ZK
aY:)*+'%',0'>ZKa0'1
FH1+7>ZKaK
F-ab+,=%',%' Z
F’".)*,-8$-"1-"0=
F(%"0$!=6>ZKa
2.Kĩ năng91-",4>Z
3.Tư duy và thái độ9:8 1'4ˆ64--*T, 6*.
6,=
K‡>8
$*+ZKa*,8%p!,<
,nJ7"0$!K*,,-

nJ79'%'0' 5/=[%'[
-VOU$UN,/7/R,Qh,56
/<T>N
7%8Q@U
:;<=>?^pUc`
FX$1@\•A%•$ƒ‚„GHI
#&NK>;@
Hoạt động 1: Tìm hiểu cấu tạo con lắc lò xo và trạng thái của con lắc^pUc`
%&/ %&H &NK
oH(Dah/!,<=
5\59
FQ7>ZKa^(X:r
>8
FI b,-%r1h•
#//)14
>Z^
Fe>Z8"1
K ^
oG41-=
5\5>H(

QˆQW\
1. Cấu tạo: [//,-• 
/Z,/Ka 

Nhận xét: b,-%,$+r1
= )/Z
K#,$+\f
Hoạt động2: Khảo sát dao động của con lắc lò xo về mặt động lực học, chu kì, tần số^pUc`
oZ7N1

=6^
o(<!/)1$7>
ZKa^
F_   665 #
%"\+=,Š$“=
\4$4>Z 
Ka€%7^
oDNyDG*•
ZK”

o:=55:
A^
o(% )* +    !
>Z^
o\ab,N,N
>= b,
oDG41-$1@
oDG41-$1@
uX1-:
A
uX$1@h4
F(%)*>= b,
,-ab=,+5/
$N=%&j=QˆQW
\*M;‰%8QVŠ
Ib,-/%r1,-=
•#/!,-N
.>=[ŒmF a
Xh-••089
Œm/

⇔
– am/
⇔
mF

/
a
C9ω
B
m
k
m
⇔
mFω
B
a85/
amlSωnϕU/vQˆN=%&
%MKW=
oX, !,>ZKa9
Tần số góc:
k
m
ω
=
C hu kì:
B
m
T
k
π

=
uLực kéo về
Fs=))N,,$+\
f
F8NŠ5,N
k
a
Œ
r
Œ
r
x
?
l

ur

ur

ur

ur
Hoạt động 3: Xây dựng biểu thức động năng thế năng , sự bảo toàn cơ năng^pUc`
* Nhắc lại các vật chuyển động
dưới tác dụng của các lực thế;
lực đàn hồi, trọng lực thì cơ
năng bảo toàn
* Trả lời các câu hỏi sau:
 P   )  *  +  '
  > ,- 8    4

^
F     )  *  +  '
>,-8 %
7^
F:0'>,-
.>%1
€4  /  *  7    ,N
$@ "  4    >
Z^

F2T$ %-,0'>
Z$

FD\•:
B
^
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1. Động năng của con lắc lò xo
B
A

B
d
W mv=
2. Thế năng của lò xo
B B
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A A
t
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k l kx= ∆ =
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toàn cơ năng .
B B
A A
B B
d t
W W W mv kx= + = +
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m
A
B
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B
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A
B
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B
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B
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A
B
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l
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B
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Suy ra:
B B B
A A
B B
W kA m A
ω
= =
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5. Rút kinh nghiệm :
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F(%*+%',0'>Z0j= b,

F-ab+,=%>',%'>Z 
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6,=
K‡>8
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/<TN
7%8Q@U
:;<=>?(5phút)
= :\•Bv$AvGHI
> :\i•$AvGHI
#(;@
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%&/ %&H &NK
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FI b,-/%r1š•
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Z^
Fe>Z8"1
K ^
oG41-=
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1. Cấu tạo:/,-•
8 /$hR

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Nhận xét: b,-%,$+r1
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o(<!/)1$7>
Z0
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7%8Q@U
:;<=>?^pUc`
FQ7ZKa,Z0)*+ !^…',%'>Z%
&#7%^
Hoạt động 19 giải bài tập trắc nghiệm(20phút)
%&/ %&H &NK
o:D6:\$Z
5/ Ei•  $  Av  
X$!4
o: D 6 : \  $Z
5/ Ei•  $  Av  
X$!4
o:61•
-"BAYBvYBEYBiX$i
,vƒ$ƒGrX
oDG6d\p
41-$
"TD1+
o  X1 - 8/ !/ $
%#1D1+
o  X1 - 8/ !/ $
%#1D1+
- Câu 4 trang 13: D; Câu 5 trang 13: D
Câu 6 trang 13: B
-Câu 4 trang 17: D ; Câu 5 trang 17: D
Câu 6 trang 17: C
BA:\lYBv:\eYBE:\l
Bir9
BB

A
B
A
B
BB
kA
kxmvw =+=

smxA
m
k
v `W•vUS
BB
=−=
vƒ:
Hoạt động 19 Giải bài tập tự luận về dao động điều hoà của con lắc lò xo và con lắc đơn (15phút)
Bài 1: ?,- b5 •
(X:r/7•/1,\
=,N8wm|S$U
j"0$!>
Z,N 59
T,-#(X:rh0
T,-#(X:rh\/
oDNy19
F(%"0$!&#>

FX4lm•/
F(-. 51!/$
Ž
( Một lò xo được treo thẳng

đứng, đầu trên của lò xo được giữ
chuyển động đầu dưới theo vật
nặng có khối lượng m = 100g, lò
xo có độ cứng k = 25 N/m. Kéo vật
rời khỏi VTCB theo phương thẳng
đứng hướng xuống một đoạn 2cm,
oDG%"
o…68/Z
oDG1-1
oDG
%"

0$!&#9amlSwnŽU
am•S|nŽU
mWamW,›W
am•ŽmW
,mF•|Ž›W
ŽmW
ŽžW
m›ŽmF|`B
(-4"$!9am•S|–|`BU/
mWamW,žW
 am•Žm•
 ,mF•ŽžW
 ŽmW
 Ž›W
 m›Žm|`B
(-4"$!9am•S|n|`BU/

=`X7,$+\fk! ∆m/

⇒∆m
0,04
25
0,1.10
k
mg
==
S/U
∆

W
WS(X:rUU
a
F∆
Ÿ
Ÿ
Ÿ
∆

W
W(VTCB)
a
-
∆
l
Ÿ
Ÿ
Ÿ
⇔
⇔

⇔
⇔
truyền cho nó vận tốc
310
.
π
(cm/s) theo phương thẳng đứng
hướng lên. Chọn góc tg là lúc thả
vật, gốc toạ độ là VTCB, c dương
hướng xuống.
a. Viết PTDĐ.
b. Xác định thời điểm vật đi
qua vị trí mà lò xo giãn 2 cm
lần thứ nhất.
* Hương dẫn Học sinh về
nhà làm câu b
o…68/Z
oDG1-1
nωm
π===
5105
1,0
25
m
k
S2`U
n/,N"0$!
amlSωnϕU
mWamB/›W
,mAWπS/`UžW

X8Bmlϕ→:ϕ›W
FAWπmFiπlϕ→Gϕ›W
m›ϕmA`
v
⇒ϕm|`vS2U→lmES/U
(-4Xe…9amESiπnUS/U
bjgN‰NW(5phút)
P:7@C",>-1-"$Z5/
F(/-"$-";
p1cfƒ;
3
3
•
i
π



ngày soạn .
ngày dạy .
TiÕt 7 3DEFG…3l/Y3DEFG
“(I
[+K9

FMC/>q4$ *,R
FH1+4\>Z
F 58Ra14$
F,,+.,/#$6>5R
F(<,1+@R
”",-. 5R1+/5,-P8#H1-"

0= 
#VNK*$%&9:8 1'4ˆ64--*T, 6*.
6,=
K‡>8
$*+r+5/>ZKa74$/C"q+5/REv
:,+.>Z$/,+,R
,/ 1$N6)-",0'>Z—m
BB
B
A
Am
ω
-VOU$UN,…/7/RX),Q,56]
/<TN
7%89
:;<=>?9^pUc`
F(%*>',%'0'>Z0R,$+85¡Q !
FIZ!',%'>Z%%^
#(;@
%&T;:KN=%&ˆNShN=%&NK<T^pUc`
%&/ %&H &NK
oX=%€4-abZ8
K ^
orZ%^
oH($Z,[
>Z
o4 \  y % 5
$^
oH(*.Z
1+0%>7


o…$$,N
$ +5x
W
orf4$!Z
)Z/ )
=$ 1@^
o…4$!
osQ4/,+./
74$!
oc+//)1-
ab
oDGd+5/$1@
oH\ 5/
oDG4Š$1@[@1
+  4  \  y  %  
Z
oDGh“%" %*

oX%" %*
u1p"'
/f/0Q$
oX%" %*
oX!//,+.
f•i;=$QˆN=%&
%MK*@Sg<+^Sg–U[
K&*$%‰Zj=ƒ`
3=%•ˆNS9
1. Thế nào là dao động tắt dần ?
Dao động mà biên độ giảm dần theo

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2. Giải thích :
e=1>/)$@SŒ
/
U/
0'>Z48
5'
⇒
l1/,d7
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r"-1/a8 ))ah/4"-
•=]
3=%&NK<T
u 3=%&%VŠNK<T>—$˜
 >+%&  f•  %9  ;  f•  Q;
=%9KfTN=%•<+j=ƒ,
QN=%&NK<T
o(+.,4$!9
 …,“@0#4[[
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E
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
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Hoạt động 2: Tìm hiểu dao động cưỡng bức(10 phút)
ĐVĐ: ?@d#4
14a
o-ab>
#4T4%^
o  ?        #4  ,y

W
 Z!@T
/!^
oH($ *
)=4Q"/
s#4p7s/Q
//
os/X!EvS:

A
U
oD6-ab>#4
oS.7=U@p
4;4
DG%"N

oD\•:
A
3=%&V™>
QN=%&V™>
n3=%&8K$N[j=;&
QrV™>KS,QN=%&
V™>
/ZN[9GHI`A„
#F‰%:;9
nƒN=%&V™>iSg>—
Sgj=QrV™>
ni>+%&f
Ž
%9,".,9
Fr>7=
F…5>7=x,N
$>5x
W
nIxfx
W
 !
 *%&N
%&#T;:KƒVŠ&VshrVsj=&Vs^ŽUc`

o:6>
 *
o  HN  5  [    >  
 *
oH1•+
oX=55:
B
o\+/#$6>
5R.
8,7>R”
uD6
uX%" %*
uD\•:
B
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ngày soạn
ngày dạy
TiÕt 8 7A-D3DEFGF€D›
-h›lHm
-- œF•/•Ež1•P•
[+K9
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A
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oX%"N
us1:\:
A
/{OLK=
&N=%&%MK*@\]D^ω_ϕ`
%VŠ>:KNŸ>—*{OLK=
MO

<+<[%&E\*{Oi
_gE

_F&NE]D
_ŠU*@<[E†
;&i>—U=
>=%SK
ϕ

-
\
\
E

W
a
?
ϕ
n
%& T;:K-VOU$U%~ž<•P•^pUc`
PsQ4/,+.
o…$
B
1[Œ$hFh
o_DGˆX
a
A
ml
A
Sωnϕ
A
U
a

B
ml
B
Sωnϕ
B
U
f,h0#4,&"
,h04
uDG%",=Q4,+.
o  D6    #    ,  h
4%$!
os1
,<
-- œF7ž1•P•
F‰*Œ%M
X!/&"Be……Dp
"0p9
A A A
S Ux A t
ω ϕ
= +
,
B B B
S Ux A t
ω ϕ
= +
e&"9
A B
x x x= +
-VOU$U%~ž<•P•

a
A
→
A
MO

H97k
…N9k?
A
ml
A


AWA
US
ϕ
=
=t
OXMO


a
B
→
B
MO

H97k
…N9k?
A

ml
A


BWB
US
ϕ
=
=t
OXMO



MO

m
A
MO

n
B
MO

,!%>8
$$.a

A B
E- E- E-= +
D49ama
A

na
B

(b0
OM
uuuur
ˆ&",
879amlSωnϕU
o(-4&">
p"0pQ/
p"0p,N
8
%&#;Dh *9ŠUF&QƒU=^pUc`
oX)*+lŽ
oe=,!,<!/7
)*l,"
Ž >&
"S:
B
U
oI ϕ
B
 – ϕ
A
 mBπ !
a
A
,a
B
^lm^

oIϕ
B
–ϕ
A
mSBnAUπ!
a
A
,a
B
%
^
m›lm^
oI ϕ
B
 – ϕ
A
 m π`Bn π !
a
A
,a
B
%
^
m›lm^:%P>
5"^
uDNy/-"(e
FDNy6,%X
  &  "  f E
91
[%,p/4+

X!/    &  "  v  
oD%"
o:8/1-!/$
*+,"
o4-ab
oG4-ab
uD4$1@
\•>,
os11
oX%"N
>(+%&hU=>=%SK9ŠUj=
=N=%&
Biên độ:
l
B
ml
B
B
nl
A
B
nBl
A
l
B
Sϕ
B
–ϕ
A
U

Pha ban đầu
A A B B
A A B B
l  l 

l  l 
ϕ + ϕ
ϕ =
ϕ + ϕ
3. Ảnh hưởng của độ lệch pha:
o%ϕ
B
–ϕ
A
mBπ9p
"m›lml
/a
ml
A
nl
B

o%ϕ
B
–ϕ
A
mSBnAUπ9
"m›lml
/
m

l F l
A B
n% ϕ
B
–ϕ
A 
mπ`Bn π9
,)8,N9
lm
B B
A B
l n l
b/ZN[9
:BK9
A
vSi US Ux t cm
π
=
,
B
ESi US U
v
x t cm
π
π
= +
X!/"0$!&"a^
H1
B B W
v E BvE•W •W‚ •AA cm= + + = ≈

W
W
W E •W
 W•„B‚ WA„
v E•W
ϕ ϕ π
+
= = ⇒ =
+


A

B
a
ϕ
∆ϕ
?
A
?
B
?
E
4
A
4
B
4
4


(-49am•ASi
WA„ US Ut cm
π π
+
bjgN‰NW^pUc`
FZ7"0"",)*
F(/-"9ABvEi•$BiGHI
/1cfƒ;
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
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1. Kiến thức:
F-$8"0""p"5$/-(-P8"0""4ˆ6
,"0""=5/

Fr%p"0""=5/a=".> !X>Z0".
,>Z%
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2. Về kĩ năng:
Fs=6Z+"%+5/
Fs=6[[@,=+"=5a !
>Z0,NŠdB£%E£
FX7+5/
F:8 '-",a•+5
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1. Giáo viên9:;/¤8/6SE→•8/U9
Fr#1\88/8$hiW
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2. Học sinh:
F…6$N=
FX$1@\•
F ¥$NR1•AS FBƒU
012345¥6
1. Kiểm tra sĩ số:
2. Kiểm tra bài cũ (kiểm tra sự chuẩn bị của học sinh).
3. Bài mới:
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Hoạt động 1. Đặt vấn đề vào bài
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FX$B•.Z8 
%^X$v^
F:6Z8%
+"^:Z^
FX1-8/75$1@\•>H(
(V@9I11R>
,N !>Z0
( 9I11R> Z
/,N !
(#9I11R>Z,N
 !
(b9Xd %#1$T$ %-
p¦.a$6$@
70/+5/
%&#$Vsj=>+%&N=%&*@KfTj=Qˆ%O
F_758/N%
+5/
n:=,NZ08
%$^
n:a8αdl^
X+α,4$85α$1•A 
FX1-8/75$1@
n…@>8α 
njα9αm
t
A
n…)@=5vW"
,N 
F:8/%h$!=N
FD€4a"/Z

=5^
HP9›BW
FXd %#1€4"-,
 !>Z0,N•^
F: !X>Z/f*•
8 )".,
4. Củng cố luyện tập:
FH(-ab@6
FDG6..=
5. Hướng dẫn học sinh tự học ở nhà:
F…6$N=%"h
FD4>4$1@+4%,@=h/yR 


1. Kiến thức:
Fr%p"0""=5/a=".> !X>Z0".
, />Z,Z%
F-, >Z0•Sα<AW
W
U,-,>
Z0
FXd=5/a)*, !>Z0
F¦.+$6$@70/+5/
2. Về kĩ năng:
Fs=6Z+"%+5/
Fs=6[[@,=+"=5a !
>Z0,NŠdB£%E£
Fr%=, %#1a•+5$T$ %-
F(<[XmxSU,X
B

mxSU
FX7=
'()
1. Giáo viên9:;/¤8/6SE→•8/U9
Fr#1\88/8$hiW
F…[[Q/\458•Q%WWA
2. Học sinh:
F…6$N=
FX$1@\•
FI¥$NR1•BS FBƒU
F:;§@Q4),<[
F:;$N1=h/y$GHI
012345¥6
1. Kiểm tra sĩ số:
2. Kiểm tra bài cũ (kiểm tra sự chuẩn bị của học sinh).
3. Bài mới:
<ŠcUj=$*+ %&j=,
Hoạt động 1. Khảo sát ảnh hưởng của khối lượng con lắc m đối với chu kì T
oH(46$1@\•9
F:=,NZ08%
$^
FG•.#1C%^
FX%%^G"/
Z^
oH(8/$R-..+5/
:TP9I4&#1C,y"1M4
>\4$h

oDG$1@\•,€
$

FeM4Z0
FX4&#1CSiWAWWAiWU
F:=5AW"
oDG%,1
•B$T$ %-9: !X/f
*•8 )"., 

Hoạt động 2. Khảo sát ảnh hưởng của chiều dài con lắc l đối với chu kì T
oH(•9
F:=Z08%
$^
F:8 !Z08žAW/
 )^X7^
oH(48/=hN
FD€4+!"0 !X
A
B
X
B
B
X
v
B
,Š
9
B
B B
v
A B
A B v

 
T
T T
l l l

FD€4,<[ˆ=".>X,>
Z0,$T$-ab
FD€4,<[ˆ=".>X
B
,>
Z0,$T$-ab
oDG$1@\•/,4

FX4&
FI)(! 8 87$
,N•Y,! !X 8
o:8/-5/,.98/
$R"\)),5
,$8/
X%,51•vGHI
F(<[XmxSUQ4X )Š5
,N
F(<[X
B
mxSUQ4X
B
Š5,N
F2T$ %-9: !X>Z
0".,>Z
Hoạt động 3. Xác định công thức về chu kì dao động của con lắc đơn

Xd[8X
B
m
B
m (N )&!
Q4$fX∼
g

FD€4a\4=*+X=,
,$6$@Sπ≈„‚ƒ≈U
F(!π
B
≈„‚ƒ⇒
B
A
„‚ƒ
π
=
⇒X
B
m m
B
g
π

FD5 70/XaQ"aŠfE
⇒Xm
B
l l
k l k

g g
g
π
π π
= =
Hoạt động 4. Ứng dụng tính gia tốc trọng trường tại nơi làm thí nghiệm
Fe=, %#1$€4+$>
7/
Xm
B
l
g
π
G4$mEπ
B
B
l
T
4. Củng cố luuyện tập
F-, >Z0•Sα<AW
W
U,-,>
Z0
FXd=5/a)*, !>Z0
F¦.+$6$@70/+5/
5. Hướng dẫn học sinh tự học ở nhà
F(%="
F…6$N•G80,=$40‘
47
474

VOHiO*i•;
 P#HiO*r<KMiO


F>80
F 5/#,N89868$48
 !N8"
F(%"0$!8
FC$>8 !4N8,'8
FX=/+5/,=$48$/\4
!"H1-"01,80
#VNK*$%&9:8 1'4ˆ64--*T, 6*
.6,=
'()
$*+:+5//)1,886,=$4>8
,J7,
-VOU$UN,/7/R,Q),56
/<TN
%&(5 phút)9:;<=>?
%&j=/ %&j=H &NK
F:;\•,e FX$1@h4
%& (35 phút)9T;:K*Zƒ;*MiO
%&j=/ %&j=H &NK
F?)1+5/,%+
5/!ƒA
FX$1@•\••:
A
^
F…80^
FI88$/CNk?

^G8$4dk%?h
"0^→G8^
F?)1+5/,%+
5/!ƒB:8-ab!)
#+5/,!,<^
F…86,/)
$@$4
FDG# %#1+5/
FD:\:
A
FX%"N
F… 5/8
/)$@$4
FDG# %#1+5/$1
@
F… 5/86
/)$@$4
HiO
AX+5/
?gG0/CN
$→?,yQ
G,d7/,/CN7k
$→?

Vậydk€$4#
NN?
B…
FG80=$4>
$//)$@
vG8

Fs80$8"0
S>Q/abU⊥
,N"0$48
EG86
Fs80$8"0
``SC$pU,N"0
$48
%&p(5 phút)jg*N‰NW
D7>H( D7>DG 
F:> %*$6\/
F_9DG/-",;

F:TPh“
Fs/-"M;

/1cfƒ;

(¦Hn/YH¤15XHn^U•`
/<T>N
%&(5 phút)9:;<=>?
%&j=/ %&j=H &NK
F_$1@•\AB•ƒ$EW FX$1@•h4
%& S10 phút)9T;:K*Mr<KMiO
%&j=/ %&j=H &NK
F?)+5/>=$4/
8!$\4!ƒv
FDG#!,<ƒv
Hr<KMiO
AG=$4>/8!
FG@mX8$4/

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G
k