某车的刹车距离y(m)与开始刹车时的速度x(m/s)之间满足二次函数，若该车某次的刹车距离为5m，则开始刹车时的速度为_刷题宝

题干

某车的刹车距离y(m)与开始刹车时的速度x(m/s)之间满足二次函数

，若该车某次的刹车距离为5m，则开始刹车时的速度为（）

A：40m/s

B：20m/s

C：10m/s

D：5m/s

上一题下一题 0.0难度选择题更新时间:2017-05-05 05:46:50

答案(点此获取答案解析）

C

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