Balenced and Unbalenced Forces

1. We have all heard of the game tug of war.  Explain how this game could have a clear winner. when one side has more force than the other.

2. Why do you think that forces happen in pairs? Because to every action there is an equal and opposite reaction.

3. I am trying to push a large box across the gym. Although I am exerting a force, the box does not move. Why could that be? The box is to heavy and you arent strong enough to push it.

4. One ball rolls along a shelf at a steady rate. A second ball rolls off the shelf and gains speed as it falls in a curved path. Which must have an unbalanced force acting on it and why?