Question

Question

Two students perform an experiment with soccer balls. They kick two soccer balls so that they collide. They measure the total momentum of the two soccer balls before and after the collision. Which statement explains why the total momentum of the soccer balls before and after the collision may not be the same?(1 point)
Responses

The system does not have any external forces.
The system does not have any external forces.

The soccer balls exert forces on each other when they collide.
The soccer balls exert forces on each other when they collide.

The system has external forces, such as friction and air resistance, acting on it.
The system has external forces, such as friction and air resistance, acting on it.

The soccer balls each have a different momentum after the collision than before the collision.

Answer 1

The correct response is:

The system has external forces, such as friction and air resistance, acting on it.

This statement explains why the total momentum of the soccer balls before and after the collision may not be the same. In the absence of external forces, the law of conservation of momentum states that the total momentum of a closed system remains constant. However, if there are external forces acting on the system, such as friction with the ground or air resistance, these can alter the total momentum, leading to a difference between the total momentum before and after the collision.