Atoms & Nuclei

JEE Main level, single correct, medium

239 of 239

Question 239 of 239

When a U238U^{238} nucleus originally at rest, decays by emitting an alpha particle having a speed ' uu ', the recoil speed of the residual nucleus is

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Answer: (A) 4u238\frac{4 \mathrm{u}}{238}

Applying the principle of conservation of linear momentum
(4) (u)=(v)(238)⇒v=4u238(\mathrm{u})=(\mathrm{v})(238) \Rightarrow \mathrm{v}=\frac{4 \mathrm{u}}{238}

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