Work Energy And Power Ques 57
57. 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
[2005]
(a) $324 $ $J$
(b) $486 $ $J$
(c) $256 $ $J$
(d) $524 $ $J$
Show Answer
Answer:
Correct Answer: 57.(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 $ $J$
BETA
