※ 引述《nonoman (nono)》之銘言：
: [領域] 大學普物                            (題目相關領域)
: [來源] University Physics 12e  Hugh D. Young
:        Chapter8 的第108習題
: [題目]
:         When two hydrogen atoms of mass m combine to form a diatomic hydrogen
: molecule(H2), the potential energy of the system after they combine is -△,
: where △ is a positive quanity called the binding energy of the molecule.
: (a) Show that in a collision that involves only two hydrogen atoms, it is
: impossible to form an H2 molecule because momentum and energy cannot
: simultaneously be conserved.
: (hint: if you can show this to be true in one frame of reference, then it is
: true in all frames of reference. Can you see why?)
在兩顆氫原子的質心坐標，形成氫分子動能守恒最後動量必需是零。可以發現這樣不可能能量守恒。

: (b) An H2 molecule can be formed in a collision that involes three hydrogen
: atoms. Suppose that before such a collision, each of the three atomes has
: speed 1.00*10^3 m/s , and they are approaching at 120° angles so that at
: any instant, the atoms lie at the corners of an equilateral triangle. Find
: the speeds of the H2 molecule and of the single hydrogen atom that remains
: after the collision. The binding energy of H2 is △=7.23*10^-19 J, and the
: mass of the hydrogen atom is 1.67*10^-27 kg.
這個就跟平常守恒問題做法一樣。

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pub 2048R/9CB5B35A 2/20/2006 Matthew Zhang (gmail key) <mathfeel@gmail.com>
    Primary key fingerprint:  9607 7903 1D12 F060 AD76 3705 5CE2 0A3E 9CB5 B35A

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