( I , )
2008
- 2 -
- 51 (07)
- 22.3
: . .-. ., .., ..- .., .. . . ., ..
: . . - .., ..
: ..- .., .., ..., . .
26 2008 ., 9.
, 18 2008 ., 1.
.
- 51 (07)
- 22.3
Ó , 2008
3
1. I 2- - ( ) 6- .
2. , 6- , 26 58. .
3. 4 (1-, 3-, 5- 7-) ( ) 22 4 50 ( 8 ).
4. , , , :
2-
. ., 07-25
: . ,
. , 2, . 5. 1 .
5. . .
6. , ( , , ). , , .
|
|
4
7. . . , , , . .
8. . , .
9. , ; , , , .
10. : .. , . .
11. , , . , , (. 4 . 14-15).
12. . , , (. 6 . 16-17).
13. , .
5
, 3520 3,52∙103, 0.00129 1,29∙10-3 ..
14. . , . ,
I.
( ) x,.
= f(t), f(t) .
Ds , Dt. Ds Dx = x1 x2 , . . Ds³O.
.
j=f(t), r=R=const.
6
, :
, at = eR, an = w2 R,
; at n ; w ; e ; R .
|
|
, = R .
n
= A cos(wt + j),
, , w , j . , :
; = Aw2 s(wt + j).
:
)
;
)
, ,
= 1 swt; = A2 s(wt+j):
a) = , j=0;
7
) = , j=p;
) =1, j=p/2
y = A cosw(t-x/ )
t, .
Dj D , :
λ .
m, ,
p =m
dp = F dt,
F , .
, :
)
F = kx,
k ( ); ;
)
P = mg;
)
,
G , m1 m2 , r ( ).
8
:
F = m g
)
F=fN,
f , N .
,
(i=2)
m1 1+m2 2= m1 u 1 + m2 u2 ,
, ;
u1 u2 , .
, ,
,
:
)
= ½ kx2
k , ;
)
,
G , m1 m2 , r ( ),
) , ,
= mgh
g ; h , ( h<<R, R ).
E=+=const.
9
, :
= F∙∆r∙cosα
:
A=DT=T2 - T1
z
z =Jze,
z z, , e , Jz .
z, :
) l , :
) ( ) , ( ):
Jz=mR2,
R ();
) ( ) R , :
Jz= ½ mR2.
z , z:
Lz=Jzw,
w .
, z:
|
|
Jzw=const,
Jz z, w z.
10
, z:
= ½ Jzw2, .
1. x=A+Bt+Ct3, A =2 , =1 /, = 0.5 /3. , x x t =2.
. , , t:
= (2+1×2 0.5 23) = 0.
:
.
, :
.
t = 2
x = (1-3×0,5×22) /= 5 /; = ( 0,5)×2 /2= 6 /2.
2. j=+t+Ct2, =10 , =20 /, = 2 /2. , r =0,1 , t=4 .
. , , t, , an, (. 1):
= at +an.
n ,
11
. (1)
t = er, n = w2r,
w ; e . at (1),
. (2)
w , : .
t=4c
w=[20 + 2(-2)4] / = 4 /.
, :
e=dw/dt = 2 = 4 /2.
w, e r (2),
= 0,1 /2= 1,65 /2.
3. 1 = 20 l=2 . m2=80 ( ) . , a=30 .
. .
, : m1g m2g N2 (. 2). . , ,
,
12
, . .
1x+ 2x = p`1x + p`2x, (1),
1x 2x ; p1x p'2x . , (1) , , 2x= 0 ( ), :
m1 1x = (m1+ 2) , m1 1 cosa= (m1 +m2) ,
1 ; 1x = 1cosa .
(2)
:
m1gh = ½ m1 , h =lsina,
|
|
= .
(2),
/c.
4. m=20 h=5 . k , ∆ =10 . .
. . , . E ( )
13
( h), ..
1=2, 1+1=2+2, (1)
1, 2, 1 2 .
, (1)
1=2. (2)
, , , . , .. 1= ½ k(∆x) 2, h, .. 2=mgh.
1 2 (2), ½ k(∆x)2 =mgh,
k=2mgh/x2. (3)
, k. (3) ( - , ):
(1×1×-2×1)/12=(1××-2)/1=1/.
, (1/), (3) :
5. m1, , m2. , , . e ?
14
. , ,
(1)
1 ; u2 2 .
(1), e u2. , . , :
M1 =m1u1+m2u2; (2)
(3)
(2) (3) :
u2 (1) m1,
, .
6. , m=80 (. 4), , m1 =100 m2 =200. , , . .
. , . : ( ).
15
( ) .
T1 - m1g = m1a (1)
m2g - T 2 = m2a (2)
T1 T2 z, , e. ,
, (3)
; ( ) z.
, , . , (3) 1 2, (1) (2):
(m2g-m2a)r-(m1g+m1a)r=mr2a/(2r).
r
(4)
(4) m1, m2 m , , . (4)
7. R=0,2 m=50 n1=480 -1
. t=50c. .
.
|
|
(1)
16
( ), z, Jz z; Dw .
Dw=w2-w1 n2 1 , w = 2pn:
Dw=w2-w1 =2pn2-2pn1=2p(n2-n1).
(1) Jz Dw,
Mz=pmR2(n2-n1)/Dt. (2)
, (×). :
(2) , , n1 =480-1=480/60-1 = 8-1:
, .
8. R=1,5 m1=180 n=10 -1. m2=60 . , , ?
. , z, , . Lz :
17
Lz=Jzw = const, (1)
Jz z; w . , , Jz=J1+J2, .
(1)
(2)
J1 J2 ; .
z p
Mo .
, J2 ( ) . ( ) J2=m2R2. (2) , (w = 2pn) ( = /R, ) ( m1R2+0) 2pn = ( m1R2 + m2R2) /R.
R2 :
= 2pnRm1 /(m1+2m2).
:
9.
. , , ,
18
(R = 6.37×106 )? , , .
: , . . .
1 + 1 = 2 + 2, (1)
1, 1 2, 2 ( ) ( , ) . 1=0, 2=0, T1= m 2 / 2, 2=mgR. , .
10. v=10. , , : xmax= 1 . .
.
x = Asin(wt + j1), (1)
; w , t ; j1 .
, A = xmax. (2)
w n
w = 2pn, (3)
t=0 (1) xmax= Asinj1,
j1 = arcsin = arcsin 1, j1=(2k+l)×p/2 (k= 0, 1, 2,...).
2p , j1 = p/2. (4)
(2)-(4)
19
x=Asin(2pnt+p/2), x = Acos2pnt,
=1=10-3,
.5.
.5
11. = 0,01 = 2.
E=0,1. Fmax, .
. :
= ½ mw2A2,
w = 2p/.
(1)
, , , , , F= kx, k ; . xmax :
Fmax=kA. (2)
k :
k = mw2=m4p2 /T2. (3)
(1) (3) (2) ,
.
20
:
12. ,
A1 = 3, A2 =2, t1, = 1/6, t2=1/3, T = 2. .
. - . t = 0. x=Acos(wt+j),
,
w = 2p/T.
:
21
a1 2. 1 = 3 2 = 2 j1= 30 j2=60 . w ,
a1 A2: A = A1 +A2 ,
( 6):
:
j=0,735 .
.6.
, , ,
x=Acos(wt+j) A = 4.84, w = 3,14 -1, j-=0,735.
13. = 20 /. , x1=12 x2 = 15 , Dj=0,75p. l t=1,2 , A = 0,1 .
: , , l, , 2p; , Dx, ,
Dj = Dx×2p/l = (x2-x1) ×2p/l..
l,
l=2p(x2-x1)/Dj. (1)
22
, (1), ,
w. w=2p/T (T=l/ ), w=2pv/l.
:
, w v , :
y=Acosw(t-x/ ), (2)
=0,1 , w=5p-1, =20 /c.
y , (2) t x.
y1=0,1cos5p(1,2-12/20)=0,1cos3p =-0,1 ;
y2=0,1cos5p(1,2-15/20)=0,1cos2,25p =0,1cos0,25p =0,071 =7,1 .
1
23
101. /. , , . h ? .
102. =5/2. , , - , , . = 0.
103. , a=60 =54 / =72/. ?
104. =10/ = 5/2. , Ds, , t=3 .
105. . =18 /. =22 /, =5 /. < > .
106. a=30 =30/. n, t t= 1c ?
107. w=p/6 /. Ds, t=4, ? , - r, , j0=p/3.
108. xy
x =A1+B1t+C1t2 = A2+B2t+C2t2, 1=7/, C1= 2/2, 2= 1/,
24
2=0,2 /2. t = 5.
109. w=1 / t= 9,9. ! R = 2.
110. R = 30 e. t , , t=4c n=2,7 /2.
111. =250 / =8 . m1 = 6 u1= 400 / . 2 .
112. , =3 /, , , , u1=4 /. u2 . m1 = 210 , m2=70 .
113. , , a=30 . u2 , u1 =480 /. m2=18 1 =60 .
114. m1=70 , =9/, m2=190, =3,6 /, . ? , ?
115. , , 1=2,5
25
a= 30 = 10/. , m2=60 ? .
116. , . . 1 = 60 , m2 = 20 . ( ) , ( ) =1/? .
117. , = 400 /, . , 40% , u1 = 150 /. 2 .
118. = 200 ( , ) =1/. , 1 = 200 . u1 u2 .
119. l=3,5 m1=200, 2=80 ? .
120. l=3 =120 . 1=60 2= 90. , ?
121. m1 =8, l=1,8 , m2 = 4.
, a = 3? . , .
26
122. , m1 =300, 2 =8. , . , .
123. m1 =1 = 4/ m2 = 2, 2=3/. u1 u2 ? , , .
124. 1 =3 =2/ m2=5 . ? , , .
125. 1 =0,5 , m2 = 120 . , .
126. 1 =4 =5/ 2 =6, =2/. 1 u2 . , , .
127. m1= 10 =300/. m2 = 200 , k = 25 /. ? , .
128. 1 = 5 = 1/ m2 = 2 . 1 u2 . , , .
129. , , .