How do you explain why air bags in cars are important during head on collisions using Newton's first law?

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This is referred to as interia. If an unbalanced force such as another vehilce hits another, than a persons air bag will then be active. Because when a car is in motion at a constant speed, that’s what will happen when an unbalanced force acts apon it.