The minimum kinetic energy needed by an alpha particle to cause the...

Given here: $N 716 + He 24 \to H 11 + O 819$

Energy absorbed in the reaction is $Q = \left({m}_{N} + {m}_{He} - {m}_{H} - {m}_{O}\right) \times {c}^{2}$

$= \left(16 . 006 + 4 . 003 - 1 . 008 - 19 . 003\right) \times 930MeV$

$= - 1 . 86MeV$

$= 1 . 86MeV$

Let $v$ is velocity of alpha particle.

Now, the maximum loss of kinetic energy= $\dfrac{1}{2} \times \dfrac{m \times 4m}{5m} \times {v}^{2}$

$⇒ \dfrac{1}{2}m{v}^{2} = \dfrac{5}{4} \times Q$

$= \dfrac{5}{4} \times \left(1 . 86\right)MeV$

$= 2 . 325MeV$

$∴ n = 2 . 33$