Лебединская. Динамика материальной точки
.pdf' 1.3
+MOMEH 9 8 :
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A . |
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M = I ε , (3.1), |
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-Dj = I d2ϕ , |
(3.2) |
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'. 3.1 |
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, ϕ+& ω ϕ = 0 . |
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. (3.4) , |
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33 |
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T( = 2p |
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I – ( (, |
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(3.6) (3.7) , |
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I = I T(2+ -1 . |
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(3.8) |
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, (3.9) (3.8), - 2-
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-1 . |
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+ ( R
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34
Ic. |
= m |
(3R2 |
+l 2 ). |
(3.11) |
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12 |
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+!# ! , !& # ! ,
1., ( , . % (T 3
t 10–15 * .
2., ( , ( *
4 . 1 4 , 3
t(+ 10–15 * .
3./ (m( d(.
4./ m , lc d .
5.' (.
6., 2
( (3.10).
7.' ( (3.11).
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8.' 2
(.
9.! ( * )
(( * ( *).
! #!&) , ! #! ,
1.9 ( : ? / ? *
( * ? 1 ?
2.9 , -4 ?
3.8 4 4
.
4.* .
5.2 ( .
6.9 7 (
( , : :?
# (#
1.! . . 1 . +. 1. – .: , 1989. – !. 94–116.
2.++. . 1 . – .: . ., 2001. – !. 34–46.
35
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'1.4 |
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9 &) # ! ,: ( |
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+# !#, |
# & . !: , , . |
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( ! * !'* # % |
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mg , ( %, |
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α |
M , (+.8), : |
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M = −mgd = −mgl sin α , |
(4.1) |
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l – 4 & |
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( %, d = l sinα – |
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4 . |
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'. 4.1 |
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T = 2π |
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(4.2) |
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mgl |
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T – , |
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4&, m – , l |
– ( |
4, g – .
(4.2.) ( ,
l , ,
t, n :
T= t /n .
( . 4.2)
1, 2 3
* 4 5. ! 4- *
:- 6.
36
! (4.2), (
( , * 4 - 2)
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mgl T 2 |
(4.3) |
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1 . |
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4π2 |
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( l , -
-4 . - . / ,
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4
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mg(L − l )T 2 |
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2
L – . &(4.3) (4.4)
. % * (
1* .
* - I1 I2
3 :
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= I |
c |
+ ml 2 |
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(4.5) |
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(4.6) |
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I2 = Ic + m(L − l ) , |
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'. 4.2 Ic – ( , *-
4 ( 4. ' :* (4.3), (4.4), (4.5) (4.6),
- (
l = |
4π2L2 − gLT22 |
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(4.7) |
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8π2L − g(T 2 |
+T 2 ) |
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l , - I1 I2
+!# ! , !& # ! ,
1.8 , .
2.L.
3.& * 46. ,-
, 15°,
20–30 * .
3-* . <t1>.
4., 3-* 20–30
* , – <t2> .
5.' *1 *2 .
6.' ( l .
7.' ( I1 I2 .
8.' (
37
5 |
m |
L |
n |
t1 |
<t1> |
t2 |
<t2> |
T1 |
T2 |
l |
I1 |
I2 |
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1
1.9 ( ( ), ?
2.9 ( ? 1 ?
3.! 3 . , .
4.9 ?
5.-
? 9 ?
6.' -4. 9 *?
7.*
4 ( . ).
8.( I1 I2 .
+# &!. (, ! # !!& %2 ' !"! *)
! (4.1) 4 (+.13)
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−mgl sin α = Iα&, |
(4.8) |
α&= ε – .
+ *
*, sinα α, (4.8)
α&+ |
mgl |
α = 0 , |
α&+ ω2α = 0 , |
(4.9) |
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I |
0 |
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mgl / I = ω2 . |
(4.10) |
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0 |
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' ( (4.9), *, |
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α = αmaxcos(ω0t + ϕ0 ) . |
(4.11) |
,
( ), -
. . (4.11) , αmax ϕ0 –
, ω0 – ( ,
ω0 = |
2π |
. |
(4.12) |
T
(4.10), (4.12) - (4.2).
#
1.! . . 1 . +. 1. – .: , 1989. – !. 94–116.
2.+ +. . 1 . – .: . ., 2001. – !. 34–46.
38
' 1.5
0
7 8 : + 7 ; :
( II – - 2
()
9 &) # ! ,: 1) ( 2-
; 2) ( ; 3) -
.
+# !#, # & . !: /, , -
, (, .
( ! * !'* # %
/, , . 5.1. /
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4 |
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'. 5.1 |
. ' h, |
t, .
/ 4
M = I ε , |
(5.1) |
M – 4-4 , -4 , I – (
, ε – .
(5.1) 2 ( . % * , , 2 * - -
* . !,
39
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ε = a , |
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(5.2) |
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R |
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– -4 , R – . |
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h = |
at 2 |
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a = |
2h |
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(5.3) |
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2 |
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t2 |
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4 * * :
*. ! F *, -4 ( . 5.1):
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r |
r |
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mg + F |
= ma , |
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mg − F = ma , |
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F = m(g − a) . |
(5.4) |
0 , 4
* ,
M = m(g − a)R , |
(5.5) |
g – .
, (5.1) (5.5) (5.2), (5.3)
2 (
I
I |
= |
mR2 |
(gt 2 |
− 2h) |
. |
(5.6) |
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2h |
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+ ( I
( -4 * ,
I = I0 + 4I + 4I , |
(5.7) |
I0 – ( * ,
, I – ( , I –
( .
, (5.7) I I ,
I |
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= I |
+ |
4m l 2 |
+ 4m l 2 , |
(5.8) |
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c |
0 |
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m – , m0 – , l – , l – ( 4(
- 4, *
).
! 2 (
, -
40
4 . % * *
* .
+!# ! , !& # ! ,
1.8 m0 l 4 ( -
), .
2./ m.
3.' 2 - ( m0 .
4.' (
+ m R m0 l t < t> h |
m l I I |
1
2
3
4
5
5. ' I I .
6.& I I * .
7., - 2,
m l , .
, -4 :
I0 = (0,0021 ± 0,0001) 2, |
m0 |
= (200,0 ± 0,1) , |
mc = (62,0 ± 0,1) , |
l |
= (27,0 ± 0,5) . |
! #!&) , ! #! ,
1.% ( .
2.% .
3.% , .
4., * . 1
? *( * - ?
5.! 3 . ! 4- ,
m0 .
6.8 4 4
. (5.6).
7.* .
# (#
1.! . . 1 . +. 1. – .: , 1989. – !. 94–116.
2.+ +. . 1 . – .: . ., 2001. – !. 34–46.
3.8 . .., + /. . 1 . +.1. – .: , 1972. – !. 59–70.
41
' 1.6
+ 0 6
+ < ; 7 : /
9 &) # ! ,: * .
+# !#, # & . !: , , ,
.
( ! * !'* # %
. 6.1 MLN -
. L – . 0 -
- %, , .
'. 6.1 |
%* R - * * 2. % * 2
( 2 mgh , , L *2 2,
2 mυ2 / 2
2 4 Iω2 / 2 .
0 *- ,
**2
mgh = |
mυ2 |
+ |
Iω2 |
, |
(6.1) |
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2 |
2 |
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m – , h – % - L, υ –
L , < –
4 , I – (
, * 4 .
42