Question

1. what is true of a system if two objects collide with different velocities and masses and come to a stop when they collide?

their impulses are different

their impulse is zero

momentum is conserved

they have no initial momentum

Explanation:

According to the law of conservation of momentum, in the absence of external forces, the total momentum of a system remains constant. When two objects collide and come to a stop, the initial total momentum of the system (before collision) is equal to the final total momentum (after collision, which is zero in this case as they stop). This implies that momentum is conserved. Impulse is force multiplied by time. Since the forces on the two objects during collision are action - reaction pairs (equal in magnitude and opposite in direction) and the time of collision is the same for both, their impulses are equal in magnitude and opposite in direction (not zero and not different). And clearly, they do have initial momentum as they were moving before the collision.

Answer:

Momentum is conserved.