Work Energy and Power - Result Question 58
61. A bomb of mass $30 kg$ at rest explodes into two pieces of masses $18 kg$ and $12 kg$. The velocity of $18 kg$ mass is $6 ms^{-1}$. The kinetic energy of the other mass is
(a) $324 J$
(b) $486 J$
(c) $256 J$
(d) $524 J$
[2005]
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Answer:
Correct Answer: 61. (b)
Solution:
- (b) From conservation of linear momentum $m_1 v_1+m_2 v_2=0$
$v_2=(\frac{-m_1}{m_2}) v_1=(\frac{-18}{12}) 6=-9 ms^{-1}$
K.E. $=\frac{1}{2} m_2 v_2^{2}=\frac{1}{2} \times 12 \times 9^{2}=486 J$
