MCQ
The momentum of a system is conserved
  • A
    Always
  • B
    Never
  • In the absence of an external force on the system
  • D
    None of the above

Answer

Correct option: C.
In the absence of an external force on the system
c
The law of conservation of momentum says that the momentum of a closed system is constant in time (conserved). A closed (or isolated) system is defined to be one for which the mass remains constant, and the net external force is $zero$. The total momentum of a system is conserved only when the system is closed.

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