book (2) Φυσική
date post
10-Jul-2016Category
Documents
view
234download
3
Embed Size (px)
Transcript of book (2) Φυσική
2008-2010
:
1-
4 , ,
:
5-
20 .
5 11
:
21-
43 &
22 23 25 33 37
43-
47
44 45
48-
56 ,
57-
67 2
57 61
:
61-
89 ( )
69 70 73 75 78 80 81
1
1. ;
.
.. xA = +3m, x = -2m -
.
2. ;
,
.
x & x .
.. , -
:
x = x - x = (3 (-2))m = 5m.
, :
xA = xA - xA = (-2 3)m = -5m.
( ).
3. ;
() .
:
: m/s
-3 -2 -1 0 1 2 3 (m)
2
km/h.
, t = 2s,
:
:
:
, , , ,
(.., , , , ).
. ,
. , -
,
4. ;
s, -
. .
100m 50 .
s = 150m.
5. .
, , , ...
;
-
(s) (t) , :
3
s1 = 200m t1 = 100s.
t2 = 50s 400m t3 = 150s. :
S = (200+400)m = 600m
t = (100+50+150)s = 300s.
:
:
: :
.
. ( )
-
.
4
1. ,
-
x1 =
4m, x2 = 2m,
t1 = 4s. x3 = 6m.
t2 = 5s. , t3 = 10s x4 = -2m.
. .
. ;
. .
. ;
2. 10km 15min.
. ;
. t =10min
;
. ,
. ;
-5 -4 -3 -2 -1 1 2 3 4 5 6 7 8 9 10 (m)
5
1. .
( ). ,
.
x t .
(1)
x = x x, :
(2)
x () t
.
:
| | (3)
( ),
.
. = -10m/s.
x = 50m ( , . ). t =
40s:
x = t = -400m s = 400m.
x = x + t = -350m.
x x -
.
:
(1) (2) .
.
,
.
6
2.
- (x t) -
( x)
( t).
t, x,
.
( t = 0)
:
-
,
.
-
, x.
(0) , -
, .
( t = 0)
, ,
:
,
.
, -
.
-0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5
-0.5
0.5
1
1.5
2
2.5
3
3.5
t (s)
v (m/s)
1 2 3 4 5 6 7 8 9
2
4
6
8
10
12
14
16
18
20
22
24
26
28
t (s)
x (m)
x
x
t
t
7
5m/s,
. t = 0,
x = -10m, .,
:
x = -10 + 5t
, t1 = 2s,
t2 = 4s .
- .
x t ( ,
):
t = (3-1)s = 2s, :
= x = 10m
,
S = 10m.
2s 4s
0 10m
-0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
-14-12-10
-8-6-4-2
2468
1012141618
t (s)
x (m)
-0.5 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5-0.5
0.51
1.52
2.53
3.54
4.55
5.56
6.57
7.58
8.59
9.5
t (s)
v (m/s)
8
1: . /.
9
1. x = 50m,
= 15m/s.
. t = 30s,
.
. ;
. =
-5m/s;
2. (x = 0)
to = 0 = 2m/s.
. t = 5s;
. 20m ,
;
. , , ;
3. 20
. t1 = 10s
1 = -2m/s. t2 = 5s 2 = 6m/s.
. 10s ;
. ;
. , (. .);
. ;
4. . 4m/s
x = -10m.
. t1 = 2s, t2 = 2,5s t3 = 5s.
. .
. .
10
. , .
5. , :
(t = 0) x = 0.
t1 = 5s x1 = 10m.
t2 = 7s. x3 =
4m, t3 = 10s
. (x-t) .
. tA(0 5s), t(5s 7s),
t(7s 10s);
. .
. ;
6.
- .
.
,
.
i)
; (
).
ii)
t = 0;
iii) ;
, :
. ( t )
.
. t = 4s.
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5
2468
10121416182022242628
t (s)
x (m)
11
1. ( ;)
, .
. ,
( ) .
.. , -
= 2m/s -
= -
1m/s2.
-
. -
,
= -
4m/s =
-4m/s2 . -
( )
m/s2 ( S.I.)
2. - .
,
. (
), -
.
, -
, . -
.
(+)
12
,
:
(4)
,
t.
(4).
,
, (4) :
| | | | | |
, -
, (-)
, .
, , -
:
(5)
:
(6)
, (5 & 6) x, -
.
,
,
, :
| |
| | (7)
13
(-) .
.
, -
, :
; !
, , :
| | | | | | | | | |
| |
;
(7) ,
!
| |
| | | |
| |
| |
| | (
| |
| |)
, :
| |
.
1. 30m/s.
4m/s2. t = 2s, :
= | | ||t = (30-42)m/s =
22m/s
:
s =||t ||t2 =
= (302- 44)m = 52m.
:
| |
| |
:
| |
14
2. x =
2m, = 15m/s = -3m/s2.
-
,
:
= + t
= [15 +(-3)2+m/s
= 9m/s
:
x = x + t + t2 = *2+152 + (-3)4+m = 26m.
:
x = t + t2 = *152 + (-3)4+m = 24m.
, , -
:
s = | | t - ||t2 = *152 - 34+m = 24m
3. , x = 0
to = 0 = - 4m/s = 1m/s2.
t1 =
2s, -
:
1 = + t
1 = (-4 + 12)m/s
1 = -2m/s.
() 2m/s.
t2 = 4s, :
2 = (-4+14)m/s = 0, .
t3 = 6s:
3 = (-4+16)m/s = 2m/s. ,
2m/s. ( ).
-8 -6 0
15
:
x = x + t + t2.
:
x1 = (-42 + 14)m = -6m
x2 = (-44+ 116)m = -8m
x3 = (-46+ 136)m = -6m.
:
x = x3 x = (- 6 0)m = -6 m.
, :
x = t + t2
= (-46 + 162)m = -6m.
3. .
. ,
, .
, . , -
.
.. = 2m/s2 = 0, -
-
. ( 2s
4m/s).
, -
,
( )
( -
). ( 2).
2: . /
(m/s)
t(s) (m/s) t(s)
0 0 0 0 4 2 4 0 = 4 2-0 = 2 8 4 8 4 = 4 4-2 = 2
12 6 12 8 = 4 6-4 = 2 16 8 16 12 = 4 8-6 = 2 20 10 20 16 = 4 10-8 = 2 24 12 24 20 = 4 12-10 = 2
16
-
,
.
, -
.
:
-
,
. , , .
1 2 3 4 5
-4
-3
-2
-1
1
2
3
4
t (s)
(m/s^2)>0
17
1 2 3 4 5 6 7
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
t (s)
x (m)
: .
;
, .
().
, , -
(
)
18
1. = 2m/s2.
t = 0 x = 4m = 3m/s:
. ; ( ).
. t = 2s;
. ;
. ;
2. = -2m/s2.
t = 0 x = 0, = 4m/s:
. ; ( ).
. t = 1s;
. t;
. ;
3. = 2m/s2.
t = 0 = -5