A 12 kg bomb at rest explodes into two pieces of 4 kg and 8 kg . If the momentum of 4 kg piece is 20 Ns , the kinetic energy of the 8 kg piece is

Question

Aicharya · Accepted Answer

The explosion is due to internal forces so the momentum of the system is conserved.

Applying conservation of momentum,

0 = m_{1} v + m_{2} v' 0 = 20 + 8 v'

v' = \frac{- 20}{8} = \frac{- 5}{2} m s^{- 1}

After the explosion,

Then,

K E = \frac{1}{2} m v'^{2}

= \frac{1}{2} \times 8 \times {(\frac{5}{2})}^{2} = \frac{1}{2} \times 8 \times \frac{25}{4} = 25 J

A 12 kg bomb at rest explodes into two pieces of 4 kg and 8 kg . If the momentum of 4 kg piece is 20 Ns ,…