A Balloon and Science When the balloon is not inflated, it has air in it. There is no pressure. When it is blown up it is filled with carbon dioxide. There are three forces that will slow or stop a rocket balloon. These three forces are friction, gravity, and air resistance. Friction is a force that resists the motion of one object or surface moving past another object or surface. The straw rubbing against the fishing line is an example of friction. Another example of friction would be the air pushing against the balloon. Air resistance are air molecules pushing against pushing against an object. When