Answer:
D. in a closed system, an object's momentum before a collision will equal its momentum after the collision.
Explanation:
As we know by newton's II law we have
so we will have
F = net force on the system
= change in momentum
so we can say if the momentum is conserved or the initial momentum of the system will be equal to the final momentum of the system
then we will say that
so net force on the system must be ZERO
so in such type of questions the system must be isolated and there is no external force on it
so correct answer will be
D. in a closed system, an object's momentum before a collision will equal its momentum after the collision.