The law of conservation of momentum applies when:

  1. kinetic energy is conserved
  2. friction is large
  3. no external force acts on the system
  4. the bodies are at rest
Answer

C) no external force acts on the system

Internal forces cancel in pairs (Newton's third law). SLO P-11-B-11 · Application

Physics MCQ · More Momentum and Collisions MCQs · Practise