Q97 / 120 · VITEEE 2013 · Physics
A body of mass $5 \mathrm{~m}$ initially at rest explodes into 3 fragments with mass ratio $3: 1: 1$. Two of fragments each of mass ' $m$ ' are found to move with a speed of $60 \mathrm{~m} / \mathrm{s}$ is mutually perpendicular directions. The velocity of third fragment is
- A$10 \sqrt{2}$
- Correct answerB$20 \sqrt{2}$
- C$20 \sqrt{3}$
- D$60 \sqrt{2}$
Solution
Using principle of conservation of linear momentum,
$\begin{array}{l}
3 \mathrm{~m} \times \mathrm{v}=\sqrt{(\mathrm{m} \times 60)^{2}+(\mathrm{m} \times 60)^{2}} \\
=\mathrm{m} \times 60 \sqrt{2} \\
\Rightarrow \mathrm{v}=20 \sqrt{2} \mathrm{~m} / \mathrm{s}
\end{array}$
Hence, the correct answer is option: 'B'.