The momentum of a system of particles is conserved if
A) there are an even number of particles in the system to allow an integer number of action-reaction pairs.
B) the net force on each particle making up the system is zero.
C) the momentum of each particle making up the system is conserved.
D) no external forces are acting on the system.
E) no internal forces are acting on the system.

Question

Quizplus · Accepted Answer

Momentum conservation in a system occurs when no external forces act on it. Internal forces, regardless of their presence, do not affect the total momentum of the system due to Newton's third law (action-reaction pairs cancel out internally).

The Momentum of a System of Particles Is Conserved If