, , . , . , ( , ) , . . : U(x).
m , U(x). ( )
,
- a ( , = ); F , ,
F = - (93)
, , . . U(x) t, : E = const.
E = + U(x), (94)
- ( ):
.
,
+ =
, :
m x" + kx = 0. (95)
( R = 0) , i = ,
, .
L q" + q = 0
+ = , ω = ,
J, , (r ).
J α" + r α = 0.
+ mgh = E, h = l (1- cos α) = 2l sin2 ≈ l , ω = ;
- J, , h.
J α" + mgl α = 0.
(94) , . (94)
. (96)
, ,
t - t0 = . (97)
- , , . . ,
|
|
U(x) < E.
, (97) .
. , , U(x) , 23. , , .
. ,
E = U(x), (98)
. , . , -
, , (92).
( 1 2 . 23.),
. .
|
. 23.
( . 23) , .
( . 9 1 2). 1 2 . , . . , 1 2 , 1 2, . .
T(E) = 2 . (99)
1 2 (94) E. . U(x).
, . U(x) . U(x) . U(0) = 0.
U(x) , , .
U(x) = U(0) + U'(0) x + U"(0) x2 + . (100)
. .
U(x) = 0 , U'(0) = 0, U"(0) . , U(0) = 0.
U(x) = ;
k = U"(0).
, ,
F = - = - k x,
m = - k x.
x(t) ,
.
. , : w0 b - . , , , , F ~ rV. , , , , b . ; w0/b0 - , . , w0/b . .
|
|
¢¢ + 2b ¢ + w02 = 0.
F= -w02x F = -2bx, (t) : , , ..
(110) w0 > b (. 26)
(t) = -bt cos (wt + j),
w2 = w02 - b2, = -bt . t - , , ..
/ = = -bt
Ne
Ne = t/ = 1/(b); = 2p/w.
,
. (104) , p , , .
1. .
E = ( )
E = (101)
(. 24).
0 . (101) :
.
, , ~ dt, , D (101):
.
, 2p (. 24).
2.
F = F0 cos wt .
,
f = - () () , w - .
( ) (86 - 87):
(t)=cos(wt+j), A(w) =
(w) ,
.
()
. (102)
.
(102) ,
A(0) =
(. 27)
, , w , b. , , , , , ,
K = (103)
, , (. 24).
3. , (87).
, w3 = 0, 618033988w0 ( )
. . , , k . . 1/ k.
|
|
A= f0/()= ( 1/ k) =( 1/ k)f0/2β (104)
(ω20 ω2)2 + 4β2 ω2 = 4 β2k2 (ω20 - β2).
ω:
ω4 + ω2 (4 β2 - 2 ω20) + ω40 - 4 β2k2 ω20 +4 β4k2 = 0.
ω12 ω22. .
ω12 + ω22 = - (4 β2 - 2 ω20)
ω12 * ω22 = ω4 0 - 4 β2k2 ω20
, β4, .
, ω1 ω2:
(ω1 + ω2)2 = ω12 + ω22 2 ω1* ω2 =
= - 4 β2 + 2 ω20 - 2 .
:
. (105)
, ( 1/k) Dw/w0 . , (. 24).
w0 , (b = 0). w0
- w w0
(80), ,
(106)
, , F0.
(107)
v (t) a(t), (106)
(107), A ( )
B = -A;
(80)
.
w w0
(. 24).
, . , , (75). t,
(108)
w0 . , , .
. 3.
3
() 10 100 ; 5 2*103 ; 3 104 ;
50;
~ 1 ;
f >1 3*104;
() 5*105;
1010;
( -) 5*106;
( ) 7,5*1012
( 0,033, 36,52 / = 4,23*10-13. 2500 ).
. 24.
.
, , , , .
|
|
β ω ( ω0). ω/β, . . . 3.
, . . 4 . , .
4
11 + ω02 = 0 | x(t) = Acos(ω0 t - j0) |
. , | |
11 + ω02 = fc | x(t) = 0 + Acos(ω0 t - j0) |
11 + 2β1 + ω02 = 0 (β < ω0) | x(t) = A0e-βt cos(ωt + j0). ω2= ω20 β2 |
11 + 2β1 + ω02 = fc (β < ω0) | x(t) = 0 + A0e-βt cos(ωt + j0). ω2= ω20 β2 |
, t. | |
11 + 2β1 + ω02 = a + bt | x(t) = A0e-βt cos(ωt + j0)+α+γt, ω2= ω20 β2, γ = b/ ω02, α = a/ ω02 - 2 β b/ ω04 |
. | |
11 + 2β1 + ω02 = f0 cosωt | x(t) = cos(ωt - j), A= f0/(), tg j = 2βω/(ω02 ω2). |
11 + ω02 = f0 sinωt | x(t) = |
, . | |
11 + 2β1 + ω02 = = f0i cosωi t | x(t) = i cos(ωi t - ji), Ai= f0i /(), tg ji = 2βωi /(ω02 ωi 2). |
11 + ω02 +sx3 = f0 cosωt | x(t) ≈ (ω02A + sA3 - f0) cosωt + cos3ωt. ( ω02) |
, .. 2- , ( 6 ). (, ), , . , , , .
x v(x). , . v(x). x v . f(x, v) = 0 v= 0 . .
.
x(t) = cos(ω0 t + α),
x(t)
vx(t) = dx/dt = -A ω0 sin (ω0t + α)
x(t) vx(t). cos x sin x, .
(109)
v() . v, . , /A ω0 , ω0.
|
|
2.1.18 .
1. , , .. 0,, v0, -, , .. v , , ( = 1)
= (v2 + 2). (110)
2. , .. . , .
3. , , . , , , .
4. , (, v) . () (. 25) 49 (.1) / 1/.
- - , - dt (. . 25). , dS , , .. dS = sin , θ .
. 25.
, , - , - , .
,
. (111)
v, = + v , - ( ) v . 1(t) = 1 + v1 = v + v1 . 1 (111).
. (112)
x = cos(ω0 t + α), vx = -A ω0 sin (ω0t + α), v1 x = d2 x/dt = -A ω20 cos (ω0t + α), (112)
. , (110).
, .
2.1.18 .
,
11 + 2β1 + ω02 = 0.
, = - 2 βy - ω02.
u = ω01x, v = y +βx, ω201 = ω02 β2,
, u v .
ω201 = ω02 β2
y2 + 2 βxy + ω02 = (y +βx)2+ ω201x2 = u2+v2,
, ,
u2+v2 = ,
(113)
, ,
ρ2 = , ρ = . (114)
, .
',, .. v,x, u = ω01x, v = y +βx, (. 26). .
, . 26 28.
. (115)
, , . (115)
= , = f (x,y) (116)
x(t), y(t), . t - , -
, . (116) , .
.26. -
u, v ¢,
.
. 27.
. 28.
, M(x0, y0)
y = 0, f(x,y) = 0,(117)
. . (117) , . , . , (116), .
:
1) ;
2) ;
3) , .. ;
4) , , , .
, (t) (116), (t), .
(, , , ..) () . () , ( ). , , () , , .
() , .. . . , , , , ( ). , , , , , . , , . () , . , . . . , , , , , . .
, :
x = cos(ωt - j) = (1 + cosn t) cos(ωt - j)= cos(ωt - j)+ cos((n+ω)t - j) + cos((n- ω)t - j) (118)
ω ω+n ω -n. . . 29. , .. . , . , , . , ( ) , .
( ) . ( = ωt, h = φ)
cosa + cos (a + h) +..+ cos[a + (n-1)h] = ;
sina + sin(a+h) +.+ sin[a + (n-1)h] = . (119)
, . , , (119) (. . 30).
, :
cosa+2cos2a+..+n cos na = ;
sina + 2sin2a +.+ n sin na = . (120)
(. 31).
/3/. .
(. 32)
f (ωt) = (121)
(. 33)
f (ωt) = (122)
, π < β t < π x(t) = exp(β t) (. 34),
f (ωt) = , (123)
k .
f(t) = sin(ω1t) :
; (124)
. (125)
:
-
; (126)
-
. (127)
f(t) = A sin(ω1t) β = 0,01 -1, ω1 = 10 / . 37 - 40.
. 29.
. 30. (119)
.31.
. 32. ( (120))
. 33.
. 34. ,
. 35. ,
. 36. , ,
. 37.
.38.
.39.
. 40.
.41. , , ,
( ) , . . , , , . , , , . (72 - 73) , , . (. 41).
, , (, ) (. 2, 2.1.14, (100)). , /5/. , ( ) (). . - ( ). , , , , .
(), (). , , . , .. , , .
, (), (, , ). , , , . , , ( ), .. . , . , .. (, ).
, :
= k1x kxy; = k1xy k2y (128)
k , y - t.
, , , , .
(128) . , .. ( ) . , 0 = const 0 = const. ,
,
(128)
k1x0 kx0 y0 = 0,
k1x0 y0 k2y0 = 0.
0 = , 0 = .
(128)
= 0 + α (t), = 0 + β(t). (129)
(129) (128), :
= k1α kx0β - k y0α kαβ,
= k1x0β+ k1 y0α + k1αβ k2β.
kαβ k1αβ , .. , 0 0 . :
= - ; = . (130)
t .
= - k1k2α. (131)
(130) t .
= - k1k2β. (132)
(131) (132) . ω0 = . , (t) (t), :
(t) = 0 + α (t) = 0 + Acos ( ω0t + φ1 ),
(t) = 0 + β(t)= 0 + Bcos ( ω0t + φ2 ).
.
() | |||
1.1 | ( ). | ||
1.2 | |||
1.3 | , | ||
() | |||
2.1 | . | ||
2.1.1. | |||
2.1.2. | |||
2.1.3. | |||
2.1.4. | |||
2.1.5. | |||
2.1.6. | |||
2.1.7. | |||
2.1.8. | . | ||
2.1.9. | |||
2.1.10. | |||
2.1.11. | |||
2.1.12. | |||
2.1.13. | , , | ||
2.1.14 | |||
2.1.15 | |||
2.1.16 | |||
2.1.17 | |||
2.1.18 | |||
2.1.19 | |||
2.1.20. | |||
2.1.21. | . | ||
2.1.22. | |||
2.1.23. | |||
2.1.24. | |||
2.1.25 | |||
3.1. | |||
3.2. | |||
3.3. | |||
3.4. | |||
3.5. | |||
3.6. | |||