Physics · Nuclear Physics

JEE Main 2024 — 9 April, Shift 2 — Question 31

A nucleus at rest disintegrates into two smaller nuclei with their masses in the ratio of $2: 1$ . After disintegration they will move

Option A:
In opposite directions with speed in the ratio of $1: 2$ respectively
Correct
Option B:
In opposite directions with speed in the ratio of $2: 1$ respectively
Option C:
In the same direction with same speed.
Option D:
In opposite directions with the same speed.

Answer: A

By conservation of momentum,

p_i = p_f

0 = m_1 u_1 + m_2 u_2

Since $\dfrac{m_1}{m_2} = \dfrac{2}{1}$ ,

\dfrac{u_1}{u_2} = -\dfrac{1}{2}

Hence, they move in opposite directions with speed ratio $1:2$ .

Answer key and solution verified before publishing.

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