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ˆF$9/140G+
;. $<, ,&,4%(,'4,-=$)>)#$%&''() ! :
/*4€0740'/7L*.
47G89@=/‰8$4040F1:
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ˆMF9>2473G"AB
ˆMF940>2473G"C2
8*4€0740'/7L*
!.47G/526 @7:
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U(/&KG9G•=/8+
.!"DE
14€!L40


‡hp!/1L"
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Ž!L40
@
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L"
@
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/Ž4€9:
/*,.>
8*M40>
J$F8OŒ//+
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26• (
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uur
(47ƒ@+%G
 947/•1(ND8…/+M4
 '+8? 7,40 !&+
,6/_†>247>9=//+
J"EL=/ /!4€$•†+V26‰8$
40/:
( )

Q Q < < Q <
‹ "  "   "+ = +
ur uur ur
'Q*
/*F7 !:]/4€/9.>+
,F'Q*•6_†…/>247/40:
( )
Q Q < < Q <
‹ "  "   "+ = +
0@0
⇒
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Q <
hp+S Qhp+<
‹ <<h Š
hp Qhp
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+ +
= = =
+ +
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:Y F69>•L<<hŠ+
8*F7 !@:]/4€/940>/+
,F'Q*•6_†…/>247/40:
( )
Q Q < < Q <
‹ "  "   "− + = +
⇒

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Q <
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hp Qhp
 "  "
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= = =
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‘‘‘
Dạng 2. FG35.H5*;I
*""!!
G3 ,&,4%(,'4"H$3) %I &/•26‰8$
40+,-’…8//=/ .L/-
L!/'>4*+
ˆJ$3) K-L
Trường hợp 1:
Z40• 6/@€‚=/•5/€!O/+
<<QQp
"""

+=
,F•4799( &+
MF26@ "M2
Trường hợp 2:
M• 6/•6+

V26@:
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L"‡<pp ŠG71+“•5/40• !L
40

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
‡}ppŠ+
/*&L=/•5///2+
8*{/=/•5/!L40
5
‡Qpp!/!O•5/C9
4•L$ŽQŠS+&LŽ1=/•5/+
5!!
/•4/4 !&!9†$/47+U/
926‰8$40+
/* R• 6@€/&//L=/•5///
<
"
uur
+

/:
Q Q < <
"  "  "= +
r ur uur
( )
Q
,6/_†>247.>98/=/•5/'>
=/7L
"
r
*+
,F'Q*•>2473/:
Q
Q
<
<
Spp Š
"  "
"  *

+
⇒ = =
( )
<
%//!• 6/&//•5/F6947
•LSppO*2
8*J
5
"
uur

L=/•5/
5
"
uur
.4
<
"
uur
:
<
Qpp Š
S
5
"
"  *= =
J
S
"
ur
L=/•5/Ž1+V26‰8$40!
8‰//:
< < S S5 5
 "  "  "= +
uur uur ur
( )
S
%
S

!L40=/•5/Ž1‰:

S Q
opp
5
     = − − =
,F'S*•>247>=/
<
"
uur
/:
< < S S5 5
 "  "  "= +
{/:
< <
S
S
S<h Š
5 5
 "  "
"  *

−
= =
0K0
%L•5/Ž1S<hO*2
LLL
Dạng 3. A*42589:.;<:<=35>?5<B:>?5
MNOP1
*""!!
* /K):
<<QQ

"""

+=
'I1<$*
'Y !&:1
 ',

<<
1
,
*
Ch :
 !&=/ 99/L4!LD=/ @
•‚9ƒ>+
 40/1
"
r



47!/→  6/
_†+
{/!F47G7=/‰F• 6/3NF
$9/140G+84>!989
2•47G7•GN9G40€$+
.!"DE
B•1/8//L
p
"
‡<hŠA/‡opG”/

$$Q!L40

‡<h!$/
@
‡Qh!+B$8/ƒ@†L
2471KL"

E‡•pŠ+j‰4L=/$@/
//!1+]OŒ/@$=/!!&+ZK ‡QpŠ+
5!!
j• ;/$+M1(26• (
D
ur
(!
!9(47E//$+U 40 !&+
J
Q
"
ur

<
"
uur
40L=/$Q$<//!”+
V26‰8$40 /:
( )
Q < p Q Q < <
  "  "  "+ = +
uur ur uur
( )

Q
0Q0
"

Q
"

<
"

'
<
*
'
Q
*
'*
α
< <
 "
uur
Q Q
 "
ur
( )
Q < p
  "+
uur
>8:
Q

"
ur
>ƒ@4†L
p
"
uur
447/+U
/9892•47G7'Q*4•GN+
:
( )
<
< <
< < Q < p Q Q
 "   "  "= + + 
 
( )
<
%
( )
Q Q
Q < p
/
 "
  "
α
=
+
( )
S
I9&L=/$Q//!/26

@:
‹< <
Q Q
<" " − =
‹< <
Q Q
< •p <+Qp+op opy< Š" "   *⇒ = − = − =
“'<*/&40:
( )
<
< <
Q < p Q Q
<
<
  "  "
"

+ +
 
 
=

≈
QhpŠ+
“'S*/:
/ <pQh
α
=
p
yi

α
⇒ =
+
M4//!•18‰”$@<8/47†•••0
47/yi
p
+
‘‘‘
Dạng 4: :CR5>?5SOI
*""!!
]&†40=/&G8F•40†=/
(26•+I9$821†‰N&†7
40=/-4-/+
,-’…/•G40(8GG!$€/

∆
KO(
1
ur
C9/+
.!"DE
Bài 1:B•1!L40Qp/8/LyppŠG‚8@
4€+I1†•Œ/4€€/
Q
Qppp
*
+{/!†•Œ/4€L=/
1Ž<ppŠ+&($=/4€26•1+
0T0
""


−‹
‹"

"

α
α
P9 5Q:
/:
( )
Q <
D  " " 1 ∆ = − = ∆
( )
Q <
ipp
 " "
1 ;

−
⇒ = =
∆
Bài 2:BŒ$8!L47‡<pp/8/L"‡<pŠG
8@4€ƒ@47•
α
‚4€+]F…L
=/Œ$8//!8A1"
E
‡<pŠ••4€
α

+
G8F•40=/Œ$8(8G 2
826•4€F€//1
ph *∆ =
+ j•
4€0:
/*
p
Sp
α
=
8*
p
•p
α
=
P9 5Q:
I8F•40=/Œ$8:
( )
‹ 
    " "∆ = − = −
uur ur
ur ur r
:
‹
<p Š" "  *= =
/892•
 
 " " " "−
ur ur

r r
4GN+/K…
G
‹
" "=
>04€
α
•7
‹
" "−
ur
r
N47‚4€
4“/:
‹
< " " "
α
− =
ur
r
%
<  
α
∆ =
'Q*
V26@
 1 ∆ = ∆
ur
/G40(
1

ur
24€26•Œ$8 .
4
∆
ur
:
< D "
1
 
α
∆
= =
∆ ∆
( )
<
‰rrrM–(8G
%
1
uur
2826•4€N47
‚4€4&/4€:
< 
%
"
1 1

α
= =
∆
( )

S
/*4€0
p
Sp
α
=
:/L@'Q*'<*'S*/G40:
i Š   *∆ =

o
%
1 ;=
8*4€0
p
•p
α
=
:
o Š   *∆ =

Qy
%
1 ;=
0U0
‘‘‘
$#-#.!"/!!
*(:VW5B1%AXO
Câu 1:B!L40ph!40!/•‚ƒ/
LhŠF/18@4€ƒ@474€+
{//140A147•L<Š+€/47

p<+Z(
1
ur
24€268/•—
n+Q}hpM ]+Q}hM ,+Q}hM U+Q}hM
Câu 2 :])Ž8•L"Ž8=…•+{/!/
1/Ž8.9>&/448=LKS
L=/8•!L408•KS!L408=+%L=/?8
//1:
n+
‹
Q
<
"
" =
˜
‹
<
S
<
"
" =
]+
‹
Q
S
<
"
" =
˜

‹
<
<
"
" =

,+
v2v
/
1
=
˜
2
v3
v
/
2
=
U+
2
v3
v
/
1
=
˜
v2v
/
2
=

Câu 3:!&
N
/2D/4€!L40

+R&4€/
@••!G4€•/L
p
"
L/+%LL
K=/!&8/•—
n+
( )
p
N"
N +
]+
( )
p
"
N +
,+
p
"
N
U+
( )
( )
p
<
N  "

N 
+
+
Câu 4 :BŽ40•†•Sp
p

47/408/
8…<!+Š“‚K+I8F•40
D∆
ur
!Ž7‚
K‰:
n+S!+Š ]+i!+Š ,+Q!+Š U+<!+Š
Câu 5:B!L40 

‡Qy}+Qp
ˆ<}
!9L "

‡
Q+Qp
}
Š/11DY'4€1
α
*/…•+{//
/.DL"
E

‡y+Qp
y

ŠŽ1
α
8/>&/4
L
"
α
‡i+Qp
y
Š+RL40=/1
α
:
n+yyo+Qp
ˆ<}
! ]+yyo+Qp
ˆ<}
!
,+ioS+Qp
ˆ<}
! U+ioS+Qp
ˆ<}
!
0$Y0
Câu 6:B!™18!L40yppp!8)47/1!L
40S}h!+R1!™-.>&//L"

‡<hŠ+
R140L8…8/•—
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n9•+Rn240Œ3
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J
Q
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Q
D
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:
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Z D     = − = −
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( )
< Q
  
α
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Q Q

 <pZ   e
α
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%=/(=/ :
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Dạng 2. 8C35^5
*""!!
R$826‰’#4€/F84/:
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p
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>/
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Dạng 3. A*42589:.;<:<=]^5
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R26‰8$7#:
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M#40-/=/ :
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Câu 1(]-/!L40hpp!7“/<
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n+yp¥ ]+}p¥ ,+op¥ U+hp¥
Câu 2:BK=/7Qpp!•+I/1•4€LSy
!Š+Z(!•=/7-:
n+QpppM ]+QppppM ,+<}}oM U+SypM
Câu 3:BŽ8!L40
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;8
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Q
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Câu 4:B4!L40Qp!40!•>•/h!$€/Q
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Câu 5:M4€/•Ž847/LQhŠ7†L
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8/†/=/8/•—
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Câu 6:B40!L“•2L2Qp•E/‚2L
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h < Š *
U+
h Š *
Câu 7:R$“/O/‚€Kh!$“K‚€+
B#•/O/KK#•K—
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Câu 8:26(1!2‰9“1•402€*
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Câu 10(,D-:
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Câu 11: Một động cơ có công suất không đổi, công của động cơ thực hiện
theo thời gian là đồ thị nào sau đây?
A. B.
C. D.
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Bài 1(BL=!L40N(•408…-
!L40+¦=40)A/@2'40!
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F:
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8* “‰&D8…!•
Q
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