Work Energy And Power Question 39
Question: A bomb of 12 kg explodes into two pieces of masses 4 kg and 8 kg. The velocity of 8kg mass is 6 m/sec. The kinetic energy of the other mass is [MNR 1985; CPMT 1991; Manipal MEE 1995; Pb. PET 2004]
Options:
A) 48 J
B) 32 J
C) 24 J
D) 288 J
Show Answer
Answer:
Correct Answer: D
Solution:
As the initial momentum of bomb was zero,
therefore after explosion two parts should possess numerically equal momentum i.e. $ m _{A}v _{A}=m _{B}v _{B} $
therefore $ 4\times v _{A}=8\times 6 $
therefore $ v _{A}=12\ m/s $
Kinetic energy of other mass A, = $ \frac{1}{2}m _{A}v_A^{2} $ = $ \frac{1}{2}\times 4\times {{(12)}^{2}} $ = 288 J.
