A radioactive nucleus undergoes `alpha-`emission to form a stable element. What will be the recoil velocity of the daughter nucleus is `V` is the velocity of `alpha`-emission and `A` is the atomic mass of radioactive nucleus ?

Options

A. `(4 V)/(A - 4)`
B. `(2 V)/(A - 4)`
C. `(4 V)/(A + 4)`
D. `(2 V)/(A + 4)`

Answer

A

Explanation

(a) According to conservation of momentum
`4 v = (A - 4) v' rArr v' = (4v)/(A - 4)`.
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