15s v1 v
A.v 1=5 m/s v 2=4m/s
B.v 1=5 m/s v 2=3m/s
C.v1=4 m/s v 2=5m/s
D.v1=4m/s v 2=3m/s
8 60kg
1.5s 5mg10m/s2
A500N B1000N C600N D1100N
9 F
A.
B.
C.
D.
10
A
B
C
D
11 PQ ABPQ A
P 90%
A B C D
12 3 2011?
A
B
C
D
13 M
1
P 1
v
2
P
k g
_______;
14 d=100m v1=5m/s v2=4m/s
