Answer:
I. The total momentum of the fragments is equal to the original momentum of the firecracker.
Explanation:
When firecracker explodes , force is generated inside cracker which is known as internal force . This force is responsible for fragments flying apart from each other . They fly apart in such a way that total momentum of all the fragments is conserved . Internal force can not change the momentum of the body as a whole. The kinetic energy is not conserved as due to transformation of energy , kinetic energy is increased .