Question Detail
Question
If the vector sum of the external forces on a system is zero,
Correct Answer
Option D is the correct answer.
Detailed Explanation
This is a direct statement of the law of conservation of linear momentum. If the net external force acting on a system is zero, the total linear momentum of the system remains constant (is conserved).
Hint
Recall Newton's second law in terms of momentum: F_net = dp/dt.