试题与答案

下列数中最接近6000的是[ ] A.五千五百 B.5550 C.5950 D.

题型:选择题

题目:

下列数中最接近6000的是[ ]

A.五千五百

B.5550

C.5950

D.5058

答案:

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1924年法国物理学家德布罗意提出物质波的概念,任何一个运动着的物体,小到电子,大到行星、恒星都有一种波与之对应,波长为λ=h/p,p为物体运动的动量,h是普朗克常数.同样光也具有粒子性,光子的动量为:p=h/λ.根据上述观点可以证明一个静止的自由电子如果完全吸收一个γ光子,会发生下列情况:设光子频率为ν,则E=hν,p=h/λ=hν/c,被电子吸收后有hν=mev2/2,hν/c=mev.由以上两式可解得:v=2c,电子的速度为两倍光速,显然这是不可能的.关于上述过程以下说法正确的是(  )

A.因为在微观世界动量守恒定律不适用,上述论证错误,所以电子可能完全吸收一个γ光子

B.因为在微观世界能量守恒定律不适用,上述论证错误,所以电子可能完全吸收一个γ光子

C.动量守恒定律、能量守恒定律是自然界中普遍适用规律,所以唯一结论是电子不可能完全吸收一个γ光子

D.若γ光子与一个静止的自由电子发生作用,则γ光子被电子散射后频率不变

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