3

J36 J

W

K W W

1K K 2K K 3K K 4K K 5K W JK 6K K 7K K 8K K 9K K

10K K

W10K

J37 J

W

KK

W FmE

KKW ( 3-1 )W AB30mBC

10m( 3-1 )W J cK J cAK

( 3-1 )

J38 J

W 1 J ACBW

S= AB + BC S= 30 m + 10m= 40m

2 J CAACW

AC = 210+230 = 31.6 m

:

m40K

W

AC31.6mK

W

K

J39 J

W 200 km/h

50km/hW

W

W

( 3-1 )

v m/sFLE S mFE t sFE

( 3-2 )W 450 km45 min K

W

s / m 66 . 166 = 2700

450000 = v

ts

= v

s 2700 = 60 45 =min 45 =t m450000=1000450= km 450 = s

K

ts

= v

Z

J40 J

W FZE

FZ80kmEW

W

Z

( 3-2 )

aW m/s2 vfW

voW tW S K

K

m/s

K

t v- v

= a f

J41 J

W 1 J K

vo vfK 2 J W

vfvo W WZ

( 3-3 )W

10m/sm/s31KK

W t= 3 s vf = 31 m/s vo = 10 m/s

2

f

s/ m7=a310 - 31

= a

t v- v

= a

m/s7K 17m/sK m/s 24K 31m/sK

J42 J

( 3-4 )W 50km/hK

Km/s2 K

W

2

ff

o

s / m 47 . 3 - = 4

89 . 13 - 0 = a

t v- v

= a

s 4 = t 0 = vs / m 89 . 13 = 2778 . 0 50 = /h km 50 = v

W FV EFaE

FtE F sEFfvEW

( 3-3 )KKKKKKKKKKKKK

WFEF aEK

2=_21

+=

+=

22

2

asvv

attvs

atvv

f

f

J43 J

F3-5WE

20 m/s3 m/s226 m/sK

a = 3 m/s,fv 26 m/sfv 20 m/s

1 JsW 2 2

f 2 2f

2 2

v v = 2 a s

v -v s = 2 a

(2 6 ) -(2 0 )s 2 3

s = 4 6 m

2 JtW

f

f

v = v +a tv -vt =

a26-20t = = 25

3

F 3-6E

80 km/h F E 2 m/s2W 1K K 2K K

J44 J

W

2f

1000v = 80 km/h = 80 = 22.2m3000

v = 0 a = 2m/s

1tW f

f

v = v - a tv - v 0 - 22.2t = =

- a -2t = 11.1 s

2sW 2 2

f 2 2 2

f

v - v = -2 a s

v - v -(22.2)s = = -2 a -22

s = 123.2 m

J45 J

K

K

K W

K W

K WW

.. ( 3-6 )

extFWK

= v 0=Fext

K

J46 J

W

W

.. ( 3-7 ) : F(N)

: m(kg) : a(m/s2) ( 3-7 )W 245gK

2.45m/s2K W

N6.0=45.2245 . 0 = Fa m = F

s / m 45 . 2 = a

kg 245 . 0 = 1000245

= g 245 = m

( F )(m)aK

am = F

J47 J

F3-8E F3-7 E NF 6.0 g490

K W

2m/s 102250.490.6a

mFa

maF0.6NF

0.49kg1000490490gm

W

22

21

1.225m/sa, g 490m

2.45m/sa, g 249m

K

F3-9WE 20 N5 kgK

W

2m/s 4m20

mFa

kg5m,N 10F

J48 J

W

22

2

m/s 2a , N 10Fm/s 4a , N 20F

K

F3 11 E kg10N80

19.6 NW 1K 2s 10

W

NF 801 N6.19 m = 10 kg F2

( 3-2) 1FaE

maF F21 , FF

F1 = 80 N 10kg

F2 = 19.6 N

J49 J

W2

21

21

21

m/s 6.04 10

6.1980 a

ma F - F -

amFF

FFF

2FsWE0v

m3021004.621 0

ta 21v

2

2

S

tS

FW3-12E kg50 N600

K W

NF 600 FWEW

gm =W

N 490 9.550

F3-3E

50kg

F = 600 N

W = 490 N

J50 J

2m/s 2.2a50

490600m

WFa

a mWFa mF

W

K F12(3-4 )

F21KW F12 = - F21

F JEF21F12

(3-4 )

W

J51 J

W

1 J K 2 J ( 3-5 )

( 3-5 )

3 J ( 3-6 )K

( 3-6 )

J52 J

1 J K 2 J WK 3 J hLkm30

K 4 J 10m/s25m/s

5sK 5 J 100km/hFE

9sKK

6hkm /362/2 sms10 W

K K

7m/s15m/s7m 90 W

K K

8 J 60 kg2s/m7K

9 J 5kg7m/s3m/s2sK

J53 J

10 J 800 NK

11K kg7 2m/s 3K 12m/s 20

N8820kg1000

W K

K 13 kg70 N400

N344K 14 Jkg70N400

344 NW K

5 sK 15kg49m/s 7s 3

K 16kg5

K