试题与答案

一个沿竖直方向运动的物体,其速度图象如右图所示,设向上为正方向.则可知( )

题型:选择题

题目:

一个沿竖直方向运动的物体,其速度图象如右图所示,设向上为正方向.则可知(  )

A.这是竖直下抛运动

B.这是竖直上抛又落回原地的过程

C.这是从高台上竖直上抛又落回地面的过程

D.抛出后3 s物体又落回抛出点

答案:

答案:C

题目分析:由v-t图象可知,速度先正后负,物体先向上后向下,A错误;图线与横轴所夹面积先有正面积,后有负面积,到2 s时正负面积相等,回到原地,D错误;到3 s末,负面积比正面积大,物体的最终位置在抛出点的下方,C正确,B错误.

故选C

点评:关键是知道v-t图像的斜率表示加速度,与坐标轴围成的面积表示位移

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