Conservation of momentum in a collision beween particles can be understood form

Options

A. Conservation of energy
B. Newton's first law
C. Newton's second law
D. Both Newton's second and third law

Answer

D

Explanation

We know that for a system
`F_(ext) = (dp)/(dt)` (from Newton's second law)
If `F_(ext) = 0, dp = 0 rArr` p = constant
Hence, momentum of a system will remain conserve if external force on the system is zero.
In case of collision between particles equal and opposite forces will act on individual particles by Newton third law.
Hence, total force on the system will be zero.
Note. We should not confuse with system and individual particles. As total force on the system of both is zero but force acts on individual particles.