质量相同的物体A和B处在同一高度,A物体做平抛运动,B物体做自由

质量相同的物体A和B处在同一高度,A物体做平抛运动,B物体做自由落体运动.从开始运动至落地过程中,它们的动量改变间的关系为(    )

A.两物体动量改变相同                       B.动量改变大小相等,方向不一样

C.动量改变大小不等,方向一样           D.动量改变大小、方向都不等

答案

A

解析:动量改变等于合力的冲量,A做平抛运动,B做自由落体运动,从同一高度下落,时间相同,合力都为重力,所以A正确,BCD错误.

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