D2 m/s
5 4
m/s 6 m/s ( )
A10 m/s,10 m/s
B5 m/s,4.8 m/s
C10 m/s,5 m/s
D0,4.8 m/s
6
A
B
C
D
7 -2J 3J
A 2J
B 3J
C 1J
D 1J
8
A
B
C
D
9 m
2m h
A
B 21
C
D
10 Q+2Q r
F
A4F B2 F C DF
11 v0 Ek 2Ek
A B2v0CD
12 AB m
1m
2. .