AB
CD
9 .
R v (
) ( )
A B
CD
10 ( )
A
B
C
D
11 d=80m v=3m/s
v=5m/s,
A. 20s
B. 90m
C.
D.
12
A J B W C kg D N
13 aa
g x1x2
x1 x2 x1+x2 x1+x2
14 m=1kg
0.04s B vB=____m/s O B
EP =____J Ek =____J g10m/s2
15 30kg 10m
g=10m/s2 ___________W;
___________J
16 2.8V 0.56W , .
