A
B
C
D
6 A.B L vA, ,v B
h
2 h'
A.h B. C. h D. h
7 AB AB s=7m AvA =4m/s
B vB =10m/s a = 2m/s2
A B
A8 s B7 s C10 s D9 s
8 2018 12 26 8 307.9
l1 350
A26 8
B 307.9
C 350
D
9 x=5t-t 2(x mt s)
v0 a
Av0=-5m/s a= -2m/s 2Bv0=-5m/s a= 2m/s 2
Cv0=5m/sa= 2m/s 2Dv0=5m/sa= -2m/s 2
10 P v02v0 AB
( )
A.AB 14
B.AB 12
C.AB 12
D.AB 12
11
