The forces acting on a body can be classified as balanced forces or unbalanced forces. If the forces act in such a way that the net force is zero, we can term such forces as balanced forces. An example is the application of two forces, equal in magnitude and opposite in direction, on a body. A boat floating in water is an example of balanced forces. If the forces act in such a way that there is a net force acting on the body, we can classify such forces as unbalanced forces. An example of unbalanced forces is an automobile that is accelerating or decelerating.
When balanced forces are applied on a body, the net force is zero. If the net external force on a body is zero, it will stay in its state of motion, without any change. That is, an object at rest will stay at rest, while an object in motion will stay at the same speed without any change. Thus, there is no change in the speed of an object if balanced forces are applied to it.
In comparison, the object will accelerate or decelerate if unbalanced forces are applied to it.