Objects 1 and 2 collide and stick together. Which best describes the momentum of the resulting single object?

Momentum is conserved during a collision, so the total momentum after the objects stick together equals their total momentum before the collision. Therefore, the resulting object's momentum is the momentum of object 1 plus the momentum of object 2, treating momentum as a vector (so direction matters). The correct choice is “It is equal to the momentum of object 1 plus the momentum of object 2.”

AI-written and checked against the verified answer.