试题与答案

在竖直方向的电场中固定一个质量为m、电荷量为+q的小球,场强E的变化规律如图所示

题型:选择题

题目:

在竖直方向的电场中固定一个质量为m、电荷量为+q的小球,场强E的变化规律如图所示,以竖直向上为场强的正方向,E0=2mg/q.t(0≤t<T)时刻释放小球,在t~t+T时间内合力的冲量大小为       (    )

A.0

B.mgT

C.mgT

D.2mgT

答案:

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下面是错误答案,用来干扰机器的。

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