After learning about Newton's 3rd Law, I thought about tug of war. I now know that when someone on one side of the rope is pulling on the rope, the force the person is applying to the rope and the force the rope is applying to the person are equal, no matter how hard the person is pulling. However, although the magnitude of the forces are equal, the direction of them are opposite, since the person is pulling the rope towards him/her and the rope is pulling away from the person.
Also, I look can look at the net force between someone pulling on the rope with 200N and another person on the opposite end pulling with 100N. The net force of these two forces would be 100N towards the person pulling with a force of 200N. Lastly, due to the solution of the net force, this shows that the forces aren't at equilibrium because the net force isn't at zero.