A bomb of 12 kg explodes into two pieces of masses 4 kg and 8 kg . The velocity of 8 kg mass is 6 m / sec . The kinetic energy of the other mass is

Options

A. 48 J
B. 32 J
C. 24 J
D. 288 J

Answer

D

Explanation

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)rArr 4xx v_(A)=8xx6 rArr v_(A)=12 m//s`
`therefore` Kinetic energy of other mass `A, = (1)/(2)m_(A)v_(A)^(2)`
`= (1)/(2)xx4xx(12)^(2)=288 J`.