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Physics · PYQ NEET UG 2019(2)
हिन्दीA body of mass \( m \) with initial momentum \( (20\hat{i} + 25\hat{j} - 12\hat{k}) \) suddenly breaks into two pieces whose masses are in the ratio \( 1 : 5 \). The smaller mass flies off with a velocity \( (100\hat{i} + 35\hat{j} + 8\hat{k}) \). The velocity of the larger piece will be,
Correct answer · Option 1
\( -20\hat{i} - 15\hat{j} - 80\hat{k} \)
Explanation
Masses are \( m_1 = \frac{m}{6} \) and \( m_2 = \frac{5m}{6} \). By conservation of linear momentum: \( \vec{P}_{\text{initial}} = m_1\vec{v}_1 + m_2\vec{v}_2 \). Solving gives \( \vec{v}_2 = -20\hat{i} - 15\hat{j} - 80\hat{k} \).
