AF1F2 1 2BF1F2 1 2
CF1F2 1 2DF1F2 1 2
7 0.2 kg 6 m/s 4 m/s
A p=0.4 kg m/s B p=- 2 kg m/s
C p=2 kgm/s D p=- 0.4 kg m/s
8 v
m R g
A.
B. F
C.
D.
9 , , , v
, , , ,
( g)( )
A
2
16
v
gB
2
8
v
gC
2
4
v
gD
2
2
v
g
10 F
A
B
C F
D F
11 ,A B v-t ,
