设AB段时间为t1、距离S1;BC段时间为t2、距离S2.
1.S1=1/2a*t1^2
1000=1/2a*t1^2
a*t1^2=2000
2.S2=a*t1*t2,t2=100-t1
S2=a*t1*(100-t1)
S2=100a*t1-a*t1^2
2000=100a*t1-a*t1^2
2000=100a*t1-2000
100a*t1=4000
a*t1=40m/s
V=40m/s
将a*t1=40m/s代如等式(1)
1/2a*t1^2=S1
1/2*40*t1=1000
t1=50s
t2=50s,a=v/t1
=40/50
=0.8m/s^2
AB段加速度为0.8m/s^2,BC段的速度为40m/s.