Question

N a closed system, the momentum before a collision _____ the momentum after a collision.

Answer 1

I had to look for the options and here is my answer:

So in a closed system, the momentum before a collision would be EQUALS the momentum after a collision happens. In thermodynamics, when we say closed system, this is the kind of system that is not affected with any force from its surroundings and still stay the same. 

Answer 2

Answer:

Equals

Explanation:

A closed system is an isolated system in which there is no exchange of mass with the environment or any other external forces acting on it. 

Due to the absence of external forces and no exchange of masses the energy and momentum of the closed system get conserved.

Therefore the momentum of the individual's objects before the collision would be equal to the momentum after the collision as only the energies get transferred but the total momentum of the system remains conserved.