Question

汽车刹车前速度为5m/s,刹车获得的加速度大小为0.4 m/s2（1）求汽车刹车开始后20秒内滑行的距离x1；（2）从开

Answer 1

1) t=a/v=5/0.4=12.5s(表示12.5s后汽车已经静止)

则s=1/2at^2=31.25m

2 ) s=1/2at^2则 t^2=2s/a=150

3) s=1/2at^2=1.25m