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> 一颗子弹沿水平方向射向一个木块，第一次木块被固定在水平地面上，第二次木块静止放在光滑的水平面上，两次子弹都能射穿木块而继续飞行。这两次相比较， A．第一次子弹的动量变化较大 B．第二次子弹的动量变化较大 C．两次子弹的动量变化相等 D．无法比较两次子弹的动量变化大小

问题：

发布时间：2020-03-13

一颗子弹沿水平方向射向一个木块，第一次木块被固定在水平地面上，第二次木块静止放在光滑的水平面上，两次子弹都能射穿木块而继续飞行。这两次相比较，

A．第一次子弹的动量变化较大

B．第二次子弹的动量变化较大

C．两次子弹的动量变化相等

D．无法比较两次子弹的动量变化大小

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