A bomb of mass 3.0kg explodes in air into two pieces of masses 2.0kg and 1.0kg. The smaller mass goes at a speed of 80m/s. The total energy imparted to the two fragments is:
Applying conservation of momentum
2×v=1×80
v=40m/s
Total energy of pieces
=12×2×40×40+12×1×80×80
=1600+3200=4800J=4.8kJ