State the law of conservation of linear momentum. It is a consequence of which law?

1. Statement: The total momentum of an isolated system is conserved during any interaction. 

2. The law of conservation of linear momentum is a consequence of Newton’s second law of motion, (in combination with Newton’s third law) 

3. Example: When a nail is driven into a wall by striking it with a hammer, the hammer is seen to rebound after striking the nail. This is because the hammer imparts a certain amount of momentum to the nail and the nail imparts an equal and opposite amount of momentum to the hammer. Linear momentum conservation during the burst of a cracker:

• The law of conservation of linear momentum holds good during bursting of a cracker. 
• When a cracker is at rest before explosion, the linear momentum of the cracker is zero.
• When cracker explodes into number of pieces, scattered in different directions, the vector sum of linear momentum of these pieces is also zero. This is as per the law of conservation of linear momentum.