FC: Summing Forces | By: Nelson Mejia
2: Forces F1 and F2 are being added. They are moving in the same direction, so the force exerted to the left is stronger.
4: Forces F1 and F2 are being neutralized because they are heading face to face with the same magnitude. This means that the locker did not moved of position.
6: Forces F1 and F2 are also being neutralized, because the forces are moving in the opposite direction with the same magnitude and angle. The locker also did not moved of position.