Brad and Erin decide to have a tug-of-war contest. Erin pulls the rope with all her might, and so does Brad. Sadly, Brad only exerts half the force that Erin does. Sarah is watching and waiting for her turn. As the forces are unbalanced, the rope moves towards Erin. Using Newton's first law of motion as a model, explain how Brad could prevent losing the tug-of-war.
