列车进站时做匀减速直线运动,车头经过站台某一位置Q时的速度为7m

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问题选择题

列车进站时做匀减速直线运动,车头经过站台某一位置Q时的速度为7m/s，车尾经过Q时速度为1m/s，则车身的中部经过Q时的速度为：

A．3.5m/s

B．4.0m/s

C．5.0m/s

D．5.5m/s

答案

答案：C

题目分析：由中间位移的瞬时速度公式，C对；

点评：解决本题的关键在于掌握匀变速直线运动的推论、公式

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