Conservation of momentum in a collision between particles can be understood from

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Ques: Conservation of momentum in a collision between particles/bodies can be understood from

(a) Conservation of energy

(b) Newton’s second law only

(c) Newton’s first law only

(d) Both Newton’s second and third law

Ans: (d) Both Newton’s second and third law

If there is no external force acting on a system (called isolated) of constant mass, the total  momentum of the system remains constant(no change) with time.

For a two system of particles in absence of any external force by law of conservation of linear  momentum.

Important point: We should not confuse with the system and the individual particles. As total external force on the system of both particles is zero but force acts on individual particles. 

Law of conservation of linear momentum is independent of frame of reference(ground level or at some height) while linear momentum depends on frame of reference. 


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